My Winterized Pool is Leaking Water!

winter pools can leak

A leaking winterized pool can cause a major headache for any pool owner. Trying to locate and resolve the leak in frigid temperatures is certainly no one’s idea of fun. So, if you suspect you have a leaking pool, here are some tips to help you find and fix it.

run through this checklist if your pool is leaking

But first, answer these questions….

  1. What type of pool: gunite, vinyl or fiberglass?
  2. What type of cover: water bag or safety cover?
  3. Was the pool losing water during the season?
  4. Have you ever lost this much water before?
  5. Is the water below the returns and pool lights?

Gunite or Vinyl?

The first question is important in that gunite pools rarely leak from the shell, with the exception of around pool skimmers. Vinyl liners can leak from anywhere from small holes or wherever the vinyl has been cut for stairs, returns, pool lights. Both types can leak water through the main drain, but this is not a common area for water loss, except on old pools or large pools that use a spring loaded hydrostatic relief valve.

what type of pool do you have?

All pool types must keep water in the pool all the time. It protects the surface and keeps the pool from floating if enough hydrostatic pressure is beneath the pool. Vinyl pools can float, too, when enough water gets underneath the liner.

Liners that leak past the shallow end floor may end up with wrinkles or a damaged pool liner when refilling the pool. Gunite and fiberglass pools can actually pop out of the ground, if enough water weight drains out.

Solid or Safety?

The second question is also important because if you have a safety cover, at least the cover won’t fall in the pool when the water drops this much. However, if a heavy snow load falls on an unsupported safety cover, it will damage the springs and possibly break some straps.

do you have a solid or mesh safety cover?

Solid pool covers with water bags will fall in the pool, slowly slipping in as the water level of the pool drops. This makes it easier to see that there is a problem with the water level, but if something is not done quickly, you risk contaminating the pool if a messy solid cover falls in the pool.

Keep the water level in the pool no lower than about 15 inches from the top of the pool coping. With not enough water in the pool solid covers fall in the pool, and safety covers are at risk for damage.

If you have a solid pool cover and use a pool cover pump, have you been pumping out pool water, through small holes in the pool cover? This is more common than you think. To avoid this, place your cover pump on an upside down frisbee and position it far away from any known or suspected holes in the pool cover.

Also, if you do have holes in a solid pool cover, tighten up the cover as much as possible, pulling out the slack and placing a few Aqua Blocks or weights around the edge to keep it taut and unwrinkled. If cover holes are near the edge, and your cover is large enough, shift the cover toward one side to bring the hole to the sloped area where the cover rises to meet the pool deck.

Pool Leak History

Questions 3 and 4 are important to the investigation, establishing any pre-existing conditions or trouble with pool leaks. Often, pool owners aren’t aware that they are losing water during the season, if it’s slow enough and there’s a lot of rain. I’ll usually ask them how much water they add during a typical summer week. If it’s more than 1 or 2 inches,  they may have had this leak for some time.

Winter Pool Leak Detection

check for pool leaks

The point at which the water stabilizes is a good area to look for a leak. Be aware that recent rain or water on top of a solid cover will raise the water level in the pool, so the leak may be below the current water level.

Water level stains (bathtub ring) or debris found stuck to pool surfaces may indicate the level or location of the leak. Looking closely around the stabilized level will usually help you pinpoint the leak, checking the pool surface and any exits of the pool, including the returns and pool light.

Step 1:

Remove the pool cover completely. Fold it up onto one side or end of the pool, where it can sit for several days or a week. Roll it up or weigh it down.

Step 2:

Mark the water level with a marker, or a piece of tape, to know if it is still leaking or has stabilized.

Step 3:

leaking pool dye test

When the water seems to stabilize for a day, inspect the pool walls closely at that point. It’s common to see debris sucked into a hole where the water is leaking out, so look for this. You can use a dye syringe to spot holes easily. Shut off the pump so the water calms and squeeze a small amount near any hole underwater. Use goggles, a mask or a clear wide glass vase to see clearly when the dye is sucked out of the pool. Leak dye can be used on anything under the water level that looks like a hole.

If the water level stabilizes at the pool light, consider that the cord conduit may be leaking. You can use a cord stopper to seal up the conduit.

Other common areas for leaking on a vinyl pool (besides the liner itself) are any other areas where the liner has been purposely cut and gasketed. This includes the gaskets for the pool light and the main drains, skimmers, returns and all three sides of steps and seats. If your water level has dropped below these and continues to leak, you can look in other areas, but always consider that there may be more than one leak.

For more information on pool leak detection, check out the article, “Find and Fix Pool Leaks.

Wait Until Spring?

In most winter pool leaks, the option to drop a hose in the pool and fill it up as needed certainly exists, and may be a better solution than fixing a leak during winter. If the pool cover has already fallen in the pool, pull the cover out, clean the pool, and try to find the leak. If you still can’t locate the leak, fill the pool (after cleaning), balance the chemistry, and put the cover back on the pool.

135 thoughts on “My Winterized Pool is Leaking Water!

  1. Jennifer Capretta

    Hi, We were scheduled to close our pool this week but what I thought was normal evaporation appears to be a leak. Our pool is inground with a liner (replaced last year by previous owner). Pool is 18.5 x 48 ft and holds about 38K gallons of water. It is losing about an inch per day. Of course, everyone is busy closing pools now and noone has time to search out a leak. Should we close it, cover it with our elephant cover and just keep filling through the winter?

    • Hi Jennifer, yes, you want to be sure it won’t drain to the shallow end floor. Look for the easy leak though, around the upper areas, the skimmer gasket and return gasket, make sure all of those screws are super tight, with a large #3 Philips screwdriver. Also check light rings and step screws if you have them. Check closely around the pool walls, corners especially, for any small holes. Holes and voids often have small clumps of debris sucked into them. You can dye test suspected leaks with food coloring, or our Dye Syringes for leak testing. Be sure that your backwash line has not been slowly leaking water, which happens sometimes, or some other notable leak (of steady flow), back by the pool system. Look carefully around the pool, and between pool and filter for any spongy soil or wet areas, and beyond, look for any run-off of water.

  2. Scott Hodges

    20 year old in-ground fiberglass pool, 25k gallons … is there a way to determine if our leak is at the main drain? (pool is open/filled for summer)

  3. Hey Dave.
    I have a liner pool w an elephant cover. I was just curious the condition today and I quickly glanced inside to notice the pool is half full. I actually stepped inside the shallow end as the water was a few inches deep. The deep end maintained its water. I tried to look for a tear as best as I could but could not find anything within the shallow end.
    Any advice?

    • As you can see from previous comments, this is not an unusual issue. With a liner pool, the vinyl liner is the first suspect, and there could be a small tear (maybe more than one), causing the leak. This could have been there during summer, but with rain and refilling, perhaps was not noticed. Second possibility is the pool light conduit leaking, and this typically will result in the water level being just below the top of the light, as much as halfway down the light. Third is anywhere the liner was purposely cut, such as the skimmers, returns, light, steps, drain. Since the water is below the skimmer and returns, those can be ruled-out. Dye testing with our Dye syringes or food coloring can test the step gasket, light gasket, and main drain. PRO TIP: any leak in a pool often has bits of tiny debris stuck (sucked) into the void, giving a visual indication. Another possibility is that the pool water level was siphoned or lowered with a cover pump, at some point, by someone, and was not mentioned or forgotten (it happens!). Some pools have an automatic hydrostatic relief valve in the main drain, mostly used on commercial pools, not common with residential pools, esp. vinyl pools, but if the o-ring is out of place, these can leak. Finally, it could be a leak in the main drain pipe, at the level of the water level, and this is most usually found directly below where the MD pipe exits the ground, in front of the filter, but can also be closer to the pool (main drain pipe leaks are rare however, so don’t freak out, just yet!). And sometimes, such winter leaks are never found, and the pool does not leak during summer. ??? Blame that on gremlins, I suppose! 🙂

  4. Hey Dave. Just noticed my concrete pool is loosing water while closed. It’s down about 3 feet. The only place left is the bottom drain in the deep end. The only change from the previous year was that I had a French drain installed. The contractor was using an excavator by my filter. Do you think they could have broke a line? If so I would think the leak would stop once the water level was below the break. Thoughts?

    • Dave, they could’ve broken the line or cracked it. It may not have been noticeable with summer rains. Some pools have automatic, spring-loaded hydrostatic relief valves, located in the main drain pot, which have a sealing o-ring. If your winterizer person used air to blow out the main drain, it can upset the o-ring, and cause a leak thru the hydrostat. Most residential pools do not have an automatic hydrostat, but some do, so it is a possibility, as are the others listed in the post above, such as pumping out pool water with a pool cover pump. You are right that the leak would stop when the water reaches the level of a cracked pipe. It may be unlikely that your drain pipe, near the filter, is 3+ feet below ground level, but it could be! Good Luck!

  5. Toni Fleming

    HELP!!!! My family pool(vinyl) has been installed since 1984 5 years ago we o.o urchase a safety cover. And ever since the pool has been leaks water only in winter months. My father replaced the safety cover last year with solid covet with bags and it is still losing water weave did the dye to check for leaks and could find anything. When we remove the cover the water level doesn’t go down at all. They company that installed the pool couldnt give my father explanation of why the water level is going down. My fathe has a pump that he keeps on cover to keep the water off to prevent any displacement of happening. If your could help us out I would appreciate it.

    • Hi Toni, since you say that the pool does not leak when the cover is removed, it could be that the cover pump is drawing water through the cover, from small holes near the pump, and actually pumping out the pool. They holes in the pool cover could be very small, sometimes the easiest way to locate them is to get underneath the cover on a sunny day and look for light peeking through. It might not be the only reason, there could be a leak in the liner as well.

  6. Dave! Found your blog and wanted to ask. Have a free form 25K gallon pool with solid winterization cover. Saw the cover was sitting low and upon draining standing water was still dipping. Decided to peel back the cover a bit and found the pool empty! It’s a liner pool and did some investigating but found no visible tears ( although may just be missing them). Pool emptied in roughly 90 days. I had my pool guy over and he seems
    to think it is a liner issue. I have a main drain but he didn’t think that would be the issue. I tend to agree because in the deepest part of the pool where main drain is, there was still about 5 inches of water covering it. Funny thing is I didn’t notice any significant water level issues all summer. Any initial thoughts? The guy are used to maintain the pool is a good friend,
    just looking for an outside opinion! Thx! Brian

    • Hi Brian, it is likely a hole in the liner, that went unnoticed with summer rains. It would be best to remove the cover to one side of the pool deck, get in the pool and carefully inspect the liner all around the current water level +/- 1-2 inches. Leaks will often have small bits of debris stuck in them. If nothing found, add a few inches of water, and watch it closely. If it holds level for 48 hours, add a 3-4″ more of water and watch closely. Some leaks or holes in deep areas are very small when the water is almost gone, but open up bigger when there is water weight on top of them. It would be best to find and fix now, and the liner may be saved. If left to sit empty all winter, it could ruin the liner. Now, it could also be the main drain line, leaking at a level that is 6″ or so above the floor of the pool, but that is rare and probably not the cause, as your pool guy says. Good Luck!

  7. My dad’s pool just started leaking and we had our pool guy come out. He found the hole that is causing the leak with the sonar scan. Our dilemma is that it’s winter and the water is almost completely gone everywhere besides the deepest area. Should we patch it with the water left in it and have a water truck level out the pool or drain it, patch it and immediately add water again in the same day? It’s the winter and it’s a vinyl lining. Our pool guy said it could work if we drained patched it and added the water afterwards in the same day but his partner called us after we set up that game plan and said since it’s winter adding water from the water truck could rip and crack the lining. Is there any opinion that can be given for us cause we wanna have it fixed before the freezing and heavy snow comes because I know lining without water pressure causes the formation to come undone. We don’t wanna wait and find out the entire pool is ruined. We don’t want the pool lining to wrinkle out or the sandy outer layer to start folding inward cause that would total the pool and cost us too much money to repair. So should we patch it with the water remaining inside and water truck the leveling, drain the water and patach it while adding water to it in the same day or drain the pool and just add a new layer and add water? The weather here is going to be between 25°-60° Farenheit if that changes anything. We really don’t know what to do here and want to get it fixed as soon as possible.

    • Hi Thomas, I would do it now. You may not have to drain it completely to patch it. (if you don’t mind some cold water, or have a wet suit). This may avoid letting the liner relax, and require a full re-set of the liner with a vacuum. You can patch it with a rubbery sealant like Anderson’s Leak Seal or EZ Patch 28, it need not be a traditional vinyl patch with glue type of patch, which is more difficult to apply underwater. You can get one truckload of water delivered and then fill the rest with a garden hose, or just fill it all from the hose(s).

  8. Margaret Graniero

    When we opened our pool this year – in-ground – it was down to just the deep end. Shallow was empty.
    Last year – it was about 2 feet down.
    Last year – my husband said maybe evaporation/displacemen – odd – but everthing seemed to be ok. So we filled it and it was fine all summer – no leaks.
    This year – he did all his checks and looked for leaks and seemed ok. So filled it. Checked the fill line constantly and nothing was moving. – not losing any water. In fact I think we only had to put water in once – and it was very little. We run our pool almost all the time. I don’t think this should matter – but before we closed the pool it was off for about 10 days – water line was not moving when the pool was off either. Pool is closed and winterized. I was just outside and it literally sounds like there is a faucet draining the water. It is tough to see under the cover but it appears to be quite low. I am having the pool guy come take the cover off and look.
    Is there anything you can think of that when a pool is off and winterized that somehow this can happen that we can have checked? But when it is open it does not leak?
    Both times our pool guys had no ideas. This year we got a new pool person just in case. any ideas would be great!

    • Hi, definitely not evaporation, and if you have a safety cover that lets water thru, it would not be displacement. If you have a solid cover (the type with water bags), if you allow a lot of water on top of the cover before pumping it off, this could raise the water level in the pool (displace it) to a point where it overflows the skimmer, or goes over the liner, or finds some other exit. If you have a solid cover and you use a cover pump, the cover pump may pull water thru small holes in the cover, pumping out the pool, thru the cover. Hope that helps? Maybe not – will be interested to know though, when you figure it out! Let us know ~

      • Margaret Graniero

        We have a safety cover.We took the cover off and the shallow end is empty. There are no visible holes. Plus this happened when we opened it this year – we filled it and it was fine all summer. We just closed it about 4 weeks ago. Just so odd this happened this past winter. Fine in summer when on. Now again – when winterized – water leaked. We can’t fill it since we can’t fix it now with the weather – so I guess we are going to have to leave the cover off all winter or we will be replacing that too! If you have any troubleshooting suggestions we would love to hear them.

  9. Perry Russom

    Can the pool drain if the main drain valve is open and the valve is in ” Winter ” position?

    • Hi Perry, not if the filter system is above water level, and the pool pump remains off during the winter. (Flip the breakers to OFF)

  10. Christine P

    I just bought a house with an above ground pool that wasn’t opened all year. I was able to fill it and clean it but it will not hold water. We were not able to use it due to how late it was in the season. The water is down to about half full which is where it was when I first uncovered it. The only thing I think I can see are sever tiny slits possibly in the bottom of the pool. There are no obvious leaks around the pool. When cleaning it I did find a couple of rose bush branches in the bottom.I need to close it down for the winter but i don’t wanna ruin the brand new cover I just bought that will sink all the way down and I don’t want to fill it up to put more chemicals in. I will be replacing the liner next year so what can I do now to prepare for next year?

    • Hi Christine, If you could locate the leaks and patch the holes, then fill the pool up and cover/close it. If that is not possible then do not cover the pool, do not add chemicals, just let it go. Just be sure to winterize (drain) the pipes, pump and filter…

  11. I removed the cover from my above ground 15x30x4 pool yesterday and the water level was about 16″ low. This was a brand new cover when I closed the pool last season. There was a lot of rain water and leaves I pumped off of the cover and I had 2 full size diverters that were totally deflated so the cover was sagging in the middle. The water in the pool was crystal clear with virtually no debris at the bottom so I’m confident the cover isn’t compromised. The water level is well below the skimmer basket and return openings with no evidence of leaks from the exterior connections. I studied the liner for about an hour and couldn’t see anything wrong. I usually lose some water over the winter but never this much. Is there an explanation other than a bad liner as to why I lost so much water?

    • HI Glen, well there are a few possibilities, either it is leaking thru the liner, or leaking thru the wall fitting gaskets, leaking thru a hole in the cover and being pumped out by a cover pump – or being pushed over the edge by a large amount of rain/snow/ice on top of the cover.

  12. Shannon Garland

    hello! We are opening our inground pool and discovered just about all of the water is gone! yikes! We assume of course there is a leak. We have a liner that has had several wrinkles for a few years but never had a problem with leaks. There is some debris in the pool, but not sure where to start. Should we have someone come out professionally to take a look at it for suggestions? We prob think a new liner is what they will suggest 🙁

    • Hi Shannon, When almost all of the water is gone – or just water remains in the deep end, one would assume that the main drain is to blame. It could be the pipe, or it could be the gasket around the main drain ring, or could be some holes in the liner. Wrinkles are suspect because the fold-over weakens the liner and it may get snagged on vacuum heads or skim nets, or by pool cleaners. If it’s not the liner, it could be the wall fittings (skimmer / returns), pool light or step section gasket. Also can be from a pool ladder leg, without using a ladder bumper, making a circular hole… Or, sometimes it’s a mishap or miscommunication with the winter cover pump, someone trying to lower the water level in the pool, but going a bit too far…

  13. Stephen C Dec

    Why is all my pool water seeping through winter cover on 28′ round above ground pool? I pump off my cover in the spring only to have approximately 10″ of water left in pool, I drained it just below skimmer and return when I closed it in the fall….Help

    • Hi Stephen, there are likely many small holes in the cover, or a separation of the ‘tapes’ used to weave the cover together. Might be time for a new pool cover?!?

  14. My pool (with a new vinyl liner put in last fall) is leaking so fast I can hardly get it filled to clean it. I’ve called a leak detection company because none of the local pool companies (including the one that installed the liner) could make time to come out to check it inside of a month. Water drained almost down to the floor of the pool over the winter. I’m losing 6-8 inches of water every 24 hours…and the leak detection company can’t come out for 2 weeks. So I have to keep some water in the pool for the liner…right? Man, I’m wasting a ton of water…and I can’t really tell where it’s going…but it’s going out fast. I assume it has to be in the main drain line for so much water to leak out…and it doesn’t stop leaking until the leak is above the remaining water in the pool. My shallow end loses all water and the deep end maybe has 2-3 feet left in it.

    • Hi Mark, at that level, I would suspect the gasket or screw holes around the shallow end walk-in steps, and then I would inspect the liner very carefully for holes at that level, which you have probably done already. 6-8″ per day is a big hole, which should be noticeable… I assume that it is going below the underwater pool light? The light conduit or gasketing can leak on pool lights. It could also be the main drain, either the gasketing, or the pipe. If you can brave the cold dirty water, you can jump down there with a Phillips head and remove the two drain cover screws, and put a #8 or #9 winter plug into the main drain pipe hole (normally on the side of the MD pot), and see if that stops the leaking.

      • Thanks for the reply. Water does go below the light fixture in the deep end, so the leak isn’t there. I’ve checked carefully for other leaks, but don’t see anything. I was able to start my pump today and have it draw from the drain only, keeping the skimmer return line closed, and it ran pretty well while I just recirculated the water some. I think the obvious sign that I have a main drain line leak was when I stopped the pump, air immediately came into the basket by the pump as the water ran back out to the low point where the leak is. If I shut the valve to that line by the pump…the air stopped coming in. So I think I’ve found my issue…now I have to pinpoint it and see about getting it corrected. I’m still shocked by the amount of water that has leaked from my pool…with no obvious outlet into the yard.

  15. Hi, I have a gunite pool that I painted with a blue epoxy a couple years ago. Over this winter, cracks emerged with water escaping from the ground into the pool. It created a white stain dripping down below the cracks and calcification. I put some concrete patch over a few areas and it seems to have worked. But there are two larger cracks that are bleeding water and it won’t stop to allow the concrete patch to dry. One I tried covering with epoxy because I thought it was closed, but now it’s bleeding water again. Is there another product to try on the cracks? This is above water level currently.

    Thanks.

    • Hi Brian, for such an issue, you would need to fill the entire crack with a sealant, from front to back. If you cannot easily reach the backside of the wall (under a deck), and maybe even if you can , you should look at Epoxy Injection kits. The process involves placing small injection ports every 2″ along the crack, epoxied in place, then injecting an expanding epoxy sealant under pressure to completely fill the crack. The injectors are then shaved off and epoxied over, sanded smooth, and then painted over again.

  16. Hi Davy, 2 years in a row since buying a new pool cover (tarp), when we open our large in-ground pool in the spring, the water level underneath the tarp in the pool itself has lowered by about 18 inches. The liner is vinyl, 15 years old, yet in the summer there’s no obvious loss of water.

    Does this mean the tarp has small holes? We have not seen any.

    Could it be that the tarp is simply porous and when we pump the large amount of water that rests on top of it, the pump is also pulling pool water through the tarp? We don’t use an upside down frisbee but we do use a spaghetti strainer around the pump.

    • Hi Dan – love the spaghetti strainer idea! The cover may be porous or have small holes. Or, there could be a small leak in the pool, which is not noticeable with summer rain and splashout and backwashing, which can make water loss hard to notice. You could do a ‘bucket test‘, to determine if the pool is leaking. Another theory I have is when the surface freezes solid, with a thick sheet of ice, this presses on the water beneath, making very tiny holes in the liner open-up larger, causing more leaking than during summer.

  17. Ken Hornback

    We have inground Gunite pool. Looked under the cover to check water level and pool was almost drained. We recently had heavy rain and snow and pool cover was sunken down. I have a pool pump on cover that pumps water all the top. I know that I could have pumped some water out but not that much. Also I noticed the last plug I put in the pool return lines in the shallow end of the pool was out. I’ve added water to the first step and I’m gonna check it in a few days. Help. Did I just bust the main drain.

    • Hi Ken, it could be the main drain pipe leaking, they can be tricky to winterize. I have another theory, a large ice sheet can sometimes put enormous pressure on the pool water, causing it to rise in the main drain pipe, to a point where it leaks out the pump (assuming no closed valve on the MD line). The pressure could have also blown out the shallow end return plug. Watch the water level closely over the next few days to see if pool is still leaking. If not, add more water to fill up more, and monitor again for a few days. Then check it once per week during the next few months, to monitor closely. And yes, pool cover pumps can pump water out of a pool, if placed near holes in a pool cover. Placing the pump on a Frisbee, away from any holes, can help avoid.

  18. Im in CA and have a 22K gallon in ground pool. The tiles fell off in one place and i can see there is something like a crack right at the tile level under the coping. My concern is this: every time it rains (and we’ve gotten a historical amount of rain here in SoCal this year) the pool fills up to almost overflowing. But a day later, the water is back down – drained out through the aforementioned crack. I’m planning on getting the problem fixed but it’s stressing me out. Should i be worried about the water draining out of that crack and into the soil/under the concrete deck? Thank you!

    • Hi Bill, i understand it perfectly, having seen such cracking many times. I call it bond beam damage, a horizontal crack behind the tile, right thru the tile and all the way to the other side of the pool wall, which is about 12″ thick at the top of the wall, under the coping/behind the tile. The problem often occurs by the lack of a proper expansion joint behind the coping. As the deck warms and expands, it pushes on the wall of the pool. So, to repair this problem must be dealt with, to create a 1/2″+ gap between the pool wall and the pool deck. Now for your question, should you be concerned about water leaking thru the wall? Yes, but in the long term. It will erode the soil under the deck and in freezing conditions, it makes the crack bigger – both over the long term. You could use pool putty or mortar mix, and fill in the crack, which lasts for a few seasons, but cracks again probably. Flexible underwater sealants can also be used. But no need to if you are going to repair soon.

  19. I have a 27 above ground pool. When water inside the pool freezes and Thaws, I noticed my return winter plug, ( white screw in plug with rubber o ring) starts to leak water back into the return hoses and then drips out of the hoses into the yard. Last year this didn’t happen. I am unable to get to the plug due to ice and water on cover. How can I make sure this leak doesn’t happen in the future? Also, how much water am I able to lose with damage to the walls ? Thank you

    • Hi Tyler, you can lose a few inches or even perhaps a foot of water without much concern. For the leaking plug, I would wrap the plug threads in Teflon tape and a bit of pool lube on the o-ring. Check that the oring is not distended (enlarged) or dry-rotted (cracked). You could also use the other kind of plug, a #9 rubber expansion plug instead of the SP1022C plug, or use both with a #8 plug deeper in the wall assy, and the SP1022C plug over top, as a double plug.

  20. Pat O'Keefe

    Hi Bob

    I’ve been having a lot of wind with my pool cover blowing it around and I’ve been noticing that when I check the water level seems to go down a little bit I fill it back up and then after about three or four weeks it goes down a little bit more is the wind blowing underneath the cover evaporating the water ? I tried to put the pool cover on the above ground pool with the bubble being bigger than normal to have the water fall off the cover and off to the sides instead of it onto the cover. So this is making the wind that’s blowing my cover around.

    • Hi Pat, a lot of people have the idea that you had, but in practice, it never seems to work well (so that the water just runs off the pool cover). For the wind, we have Cover Clips, Cover Seal, Wall Bags and Spider Cover Saver. You can also lay long inground water tubes up against the wall, on top of the pool cover. Most people use cover clips or cover seal however. However a little wind getting under the cover will not normally cause water loss, or much evaporation. the pool liner may have a slow leak. Also, for a cover pump, be careful not to place the pump near any holes in the cover, or it can pull water from the pool thru the hole, and pump it out!

  21. Ronda L Kearns

    Hi Bob,
    I live in the northeast. I have an 18 ft above ground pool. Half of the pool water has leaked out through the skimmer plug. The plug is no longer sitting snug. We opened the pool back up in November to take a look and could see through each side of the plug which is made of Styrofoam. I have no idea what to do at this point. The pool cover is concave and I’m trying to keep the snow and ice melt siphoned so there isn’t too much pulling pressure on the sides of the pool. Putting water back in at this time of year isn’t really an option and it would only come right back out with the weight of snow and rain pushing down. Any suggestions? Thanks!

    • Hi Ronda, I think that you may need to buy a small cover pump, to pump off the rain water and snow melt. If the rain water is pushing the water (under the cover) up to the skimmer level and then leaking out of the skimmer, then the water on top of the cover is way too deep. 1/2″ should be the maximum depth of rainwater on top of the cover. Siphoning the water can be ineffective.

  22. Hi, have a 12X24 AG pool that seems to lose water when covered for the winter. This is the 3rd year where it seems to lose about 1-2 inches a week during the fall months, more when it warmer (above 60). Doesn’t appear to be a leak as we don’t have issues in the summer or when the pool freezes. Is it normal to lose water when the pool is covered/closed for the winter during fall months? If evaporation, what is considered normal Thanks

    • Hi Bob, most covered pools do not evaporate very much, even mesh covered pools. However if you use one of the floating mesh covers (for ag pools), I would think it probably is normal. On a hot summer day, a sunny pool can lose a 1/4″ of water to evaporation, per day. Solid ag covers however, should not be allowing any evaporation, unless they are very loose fitting around the edges, then perhaps you would see condensation dripping around the pool, but not noticeable in the water level, I wouldn’t think…

  23. Susan Roll

    we have an older 27′ round above ground pool we replaced the liner this spring had a great summer we closed up the pool last weekend for the winter as usual then yesterday i noticed the the cover had sank in and one side looked like water had run out so we looked inside and noticed that the liner had pulled off the side half way around the pool ….what can we do

    • Hi Susan – well, the liner has come out of the track, about half of the pool circumference? Bummer. Pull back the pool cover to expose the side, and work on pulling the liner back up into the track. It may be necessary to lower the water 12″ or so, to make the task easier. Once the liner is back in the track, consider using Liner Lock in areas where the bead is loose in the track. Also inspect the track for any broken areas, which could be the cause of the problem. Another cause of the problem, since the liner is new, is that the liner is either too short or too tall for the wall height, or the floor was raised (or lowered) to cause the liner to be too tight or too loose in the track. In either case, use Liner Lock to shim the bead into the track securely. If it pops out again, consider pulling out the liner, adjusting the floor height, and resetting the liner again, preferably now before winter if possible.

  24. […] detection and leak repair is a topic discussed at length on this blog, here, and also here. Swimming pools can leak water from almost anywhere in the pool or plumbing, but there are no less […]

  25. Hi Davy –
    We had a pool service come out and open up our pool. (It’s a 2002 liner in ground pool.) Over the following days while cleaning it, we noticed it loosing a LOT of water. Turned off the pump and within 24 hours had lost 3-6 inches! 10 days later with no pump running it’s still loosing water – currently it’s below skimmer & the lights but I also add about 3 inches a day to try and protect further damage to the liner.
    We’ve no idea where the water is going to – no damp stops anywhere . . .
    It would seem to me that the liner is not our problem . . . since we didn’t loose any water over the winter – it was filled to the brim when opened.
    Think maybe that floor heads would be a better bet . . . our pool service company keeps pointing to the liner . . .
    Any ideas?
    Thanks

    • Hi, it’s usually either the liner, or a gasket on any one of the many fittings that are cut into the liner – skimmer, drain, returns, steps, lights, and did you mention floor heads, like an infloor cleaning system? Lots of opportunities there. When a pool leaks with the pump on or off – at the same rate – that does tend to point less to the equipment and plumbing, and more to the liner -or- the gasket around any one of the numerous holes purposely cut into the liner. Since you say the pool is below skimmer and lights, I would suspect the floor heads, drain or step. To find it, dye testing can be done, either by someone that can hold breath for 30-40 seconds, or with scuba equipment. Most large leaks like yours will have small bits of debris stuck into the void, a tell tale sign, so I would inspect for that first. There is a gasket under each floor head and each drain cover ring. Also could be a hole in the liner. A fairly large one, or many small ones. Good luck!

  26. DJ Schenk

    Hello Davy! I have a large inground pool, built by Polynesian Pools Inc about 35 years ago at the house I bought in 2013. The vinyl liner was replaced in 2007, confirmed when I bought. Making it 11 years old this opening season. I used a hard cover (tarp) to cover during closing in the fall (mid September, live in Cin,OH) as I usually do. Dropped water level a few inches below return line to close (no pool lights). After about two months I noticed the cover lying on the shallow end floor, and continued to monitor. After another month, late Nov, early Dec, it had continued to drop pulling the cover into the pool in the deep end. Was very nervous about the leak. We had a cold winter so it was ice for months. Recently removed the cover, 2ft left in deep end, and as you can imagine had to remove a lot of gunk from deeep end to check the issue. I assumed a tear in liner where the water stopped, or main drain meeting ground water level, or main drain clogged stopping the leak. After removing cover, and pumping out remaining water, no major tears in vinyl liner, and filled drain with clear water (until it filled pipe obviously) used food coloring and monitored water level. No evidence of leak. After talking to local pool store, I was hoping to find a hydrostaic relief vavle open from pebble or debris, although only common in concrete pools. There was another connection at the bottom of drain “bucket” but just female plug. So I assume no relief valve. The local pool store also said it could be a lot of pin holes in the liner or seams. Which I do not see. Should these pin holes be very visible? Either way I have decided to schedule an estimate to replace the liner, but I feel it might not be the problem. Even though the drain bucket did not leak after filling it when I drained the pool, I would think simple physics would tell me it still could be in drain pipe leading to the pump at the height the water stopped leaking! However, I would be shocked a small crack would cause such a major leak. I believe it was plumbed with polypipe being such an old installation however….which is not reliable after this many years…what do you think? Should i have a company come out and check the main drain piping and how much air pressure it can hold to detect a leak? I think its smart to replace liner now as well, but I’m not confident that’s all it could be….Sorry I wrote a novel! Let me know your opinions and thanks!

    • Hi DJ – yes you may as well pressure test the main drain pipe, or from the main drain pot to the main drain valve at the pump. You could hire someone to do it, or if you are feeling DIY… you could build your own PVC pressure testing rig. Plug the main drain, and insert the pressure test stick into the main drain pipe at the pump (you may need to separate or cut pipes). Pressurize the line from a garden hose, and see if it holds pressure on the gauge. It could be pinholes in the liner, those are not easy to spot, It could also be a bad gasket around the main drain, you may want to go ahead and replace it. You may have dye tested the drain – but some leaks like main drain gaskets, or liner pinholes… don’t leak much until there is thousands of gallons of water on top of it, adding pressure.

  27. Carolyn Schilstra

    In the fall we lower the water level of our inground vinyl pool to just below the jet holes. Then we blow out the lines and seal them for the winter.We do the same thing every year. This spring when we opened our pool the water level was below our steps. At least down 2 feet to the point where there is only maybe 1 foot of water in the shallow end. It has stayed at that level now for one week. This makes me think that maybe the stairs are leaking. I added about a foot and a half of water, to see if it would continue to leak below the stair line but now the water has not gone down at all in two days. Any explanation for this?? Should I continue to fill the pool? Or wait for the leak detection people to come?

    • Hi Carolyn – I would fill it up and start the system. I’ve heard this particular issue a lot this year – it is a bit puzzling. Some possible explanations are when a pool is covered with a solid winter cover that has a few holes in it – the cover pump pulls water through the holes and pumps it out of the pool… the second possible answer is very heavy snowfall and ice, which puts a lot of weight (and pressure) on the water, which can open up very small weepers into full-on leakers. Could be a leak in the step gasket or liner, which now without the pressure, has nearly closed up. Sometimes leaks in gaskets or vinyl liners can seal themselves up when they get clogged with enough small debris, to form a plug. This is temporary of course. Another possible – heavy snow can raise the level of the water in the pool, to a very high point where it leaks out above the liner, or out of the skimmer lid. In both cases, when the snow melts, the water level is now lower.

  28. Stephanie

    Last week my parent had issues with ingound pool leaking. Come to find out flex pipe has sever holes in it. (No one can figure out what could have caused these holes) Concrete around the pool was dug up pipes were replaced by hard piping. Fast forward to this year. Winter cover is pulled back and water has gone down significantly since pool being closed down in September. Last year pool was pressure test prior to the piles being replaced and again after. We are at a complete loss of what could be causing the now leaks. Any ideas? Also pool is in the Midwest and this will be the 10th pool season.

    • Davy Merino

      Flex pipe holes could have come from earwigs, a bug that likes to eat flexpipe. Pool light is always suspect, especially if the water level is at the light, or the top 1/3 of the light lens. The conduit can be sealed with a Cord Stopper, a fairly easy way to seal up the light cord, where it enters the conduit. Also, if the winter cover is a solid cover that you pump off – and it has holes in the cover, you could end up pumping pool water thru the holes with a cover pump.

  29. Hi Davy,
    have a 8 year old gunite in ground pool. since the 1st year i have always had to add a hose every 1-2 weeks and add in 4-5 inches but not consistent. every year i close the pool i would lose about 8-12 inches. always was suspect of the lights leaking. but last year i lost the complete shallow end with only about 6 ft in the deep end which was below everything except for the main drain. emptied the rest out and found a leaf in the hydrostatic valve and also replaced it…still had some water loss through the summer but thought may have found problem? this year just took cover off, solid tarp cover, brand new last year with no holes. now down 3 ft or so, not as much as last year but still below all except the main drain, doesnt look like hydro valve opened bc cant see any dirt or mud at all that may of came in…almost seem like cant be cracked pipe bc it should have leaked same amount as year b4 or should it have? its all very frustrating and i really want to figure this out!

    • Davy Merino

      Hi Chuck, could be the automatic hydrostatic relief plug again, which has an o-ring that can pop-out of position, sometimes (my theory) during winterization, when blowing air thru the main drain. You don’t have to have a spring-loaded, o-ring sealed hydrostat, you can replace it with just a plug, unless you have a high water table, or in a depressed area, topographically. I would try that, replace with a non-automatic hydrostat plug, or other threaded plugs, threads sealed with Teflon Tape. If it still leaks, pressure test the main drain, or put a plug in the main drain and monitor for water loss, to see if the drain line may be cracked (usually not).

  30. I have an above ground pool and I have the winter cover on it. I didn’t drain any water out of the pool when I covered it. Well, the pool is now only half way full as I can tell by the cover sagging into the pool. There are NO areas around the pool that are wet at all. What is going on? This happens every winter.

    • Davy Merino

      Hi Mark, probably a small leak in the pool liner, it won’t always wet the ground around the pool, in fact usually not. Also could be a hole in the pool cover, and the cover pump ended up pumping water thru the hole and out of the pool, happens sometimes. couldn’t be anything else, really! Good luck in finding it fast and fixing it easy!

      • Hello, I had the same issue with my above ground last winter. I lost at least half of the water. After taking the cover off, I carefully inspected the liner and found no leaks. Filled it up, and had no problems all season. The cover was getting old, so I bought a new one for this past winter. Unfortunately, it happened again this winter even with the new cover. I spoke with the folks at mt local pool supply, and they told me that the weight of rain/snow/ice on top of the cover can push the water out of the pool. Kind of like getting into a bathtub that is too full. The water goes over the edge. Does that sound feasible to you?

        • Davy Merino

          Hi Jeff, yes that can happen, if you don’t pump off the cover all winter, and the cover fills up with 6″ or 12″ of water, it will push pool water over the edge of the wall, or out wall returns/skimmer if not plugged. Another possibility is that when a winter cover has a foot of water on it, or perhaps ice – this weighs a lot, and can open up very small voids into a seeper or weeper, which don’t normally leak (at normal water levels).

    • Jim Custred

      Hello I think I have the same issue; opened my pool this week and vinyl liner has wrinkles and missing a lot of water; I think my root cause may be the hole in the winter cover and pumping out pool water after a heavy snow.

      My question is what do I do now? Try filling pool and hope wrinkles go away? Or drain completely?

      • Davy Merino

        Hi Jim, it depends how bad the wrinkling is, and how old the liner is, and maybe how long ago this happened. What sounds like happened is the water was mostly pumped out of the pool (or can also happen with a leak), and this relaxes the liner, and the weight of the water tends to pull the slack deeper into the pool, creating the wrinkles. Vinyl has a memory – so, wrinkles in place for long periods of time can be difficult to pull out completely. Second issue for some folks, is that a very old liner may ‘snap!’ when trying to reset (restretch) it back into shape, after it has shrunken somewhat. So what to do Jim? If the liner wrinkles are not too bad, just a few, maybe let it be. If you can’t live with it (and wrinkles are a problem in that they look ugly, but also trap dirt and are easily snagged, creating holes, etc…), then for an inground pool, you would drain the pool completely, every last drop, hosing the pool clean. Then set-up 1 or 2 powerful Wet/Dry Vacs, 5hp or more, or use the Cyclone Liner Vac. Insert the vac hose thru the skimmer top and behind the liner, between the liner and the wall. Seal up around the hose and skimmer lid with plastic and duct tape. Turn on the vac to suck all the air from behind the liner, and push and pull on the vinyl at the same time (quickly) to pull wrinkles toward the wall. It may not be completely successful, as I mentioned that vinyl has a memory. If it fails, maybe you live with it this summer, and replace next year, or take a look at our inground liners. 🙂 Now if you have an aboveground pool, the process is similar, but you may not need to vacuum, if you can manually pull and push all of the wrinkles to the side. Overlap style liners can be pulled over the wall more as wrinkles are pushed to the wall. When needed, sand bags or other (soft) heavy weights can be used to help pull apart wrinkles, and hold the vinyl in place, until the water level is high enough to hold the vinyl in place, usually 6-12″.

  31. Hello, Davie,

    We have an A/G pool with a deep end that was brand new last summer. We have pool crete underneath instead of just sand. We did not notice any leaking all winter, and when we removed the pool cover a few days ago, the water level was where it was when we closed the pool in October. However, when we filled the pool, we noticed lots and lots of water leaking around the entire shallow end on all sides! We cannot figure out how we have lost around 5 inches over the last 4 days when no one has been in the pool, and it’s all coming from around the shallow end where there is no filter, returns, lights, or anything that has gaskets. Would a leak anywhere in the liner cause that much water to be pooling around the shallow end and on all sides? Thank you for any support you can give!

    • Davy Merino

      Hi Ryan, normally a liner leak will ‘daylight’ in the general area of the leak, but it could be anywhere around the shallow end, or on the floor, but probably up on the top 5″ of the wall, normally.

  32. Anita Radney

    I put the winterzied my in ground pool and covered it late September- it’s march and I looked out and noticed there is hardly any water left in the pool!
    Should I add water so the vinyl liner doesn’t collapse? I had this issue last year called the company who just put the liner in and they said I had sucked out the water with pump but this year no pump and pool still emptied out! HELP! Just spend 5 thousand for liner and everything

    • Davy Merino

      Hi Anita, Check the water level, and if it is above the shallow end floor, then yes, add water to refill to about 80% full. If the floor is nearly dry, and the liner has pulled away from the pool, you may want the company to ‘reset’ the liner, with the vacuum, and then refill, to avoid wrinkles in the liner. It is possible to pump water out of the pool through a hole in the pool cover, but not so common. So, your pool has a leak, maybe in the liner, maybe in the main drain gasket. Not necessarily the pool companies fault – the leak could have happened during your first summer, or it could be a leaking gasket or something that was caused by them. But I cannot say – you will have to do a leak detection process, to determine where the leak is, and that may take a few weeks of casual experiments, (in-season), or hiring an expert with specialized leak detection equipment. For now though, I would just refill the pool most of the way, unless the pool is completely empty, and the liner has pulled away from the wall, as mentioned, as refilling it without resetting it could (not always) produce wrinkles as it fills.

  33. Al Ritchie

    I closed my in ground pool in the fall. A month after closing pool I heard a gurgling noise coming from the pool. I pulled the elephant cover back and shocked to see my water lever was just below the step return. Fast forward five months, temps in 50’s I pulled the cover back to check on water level and was shocked to see water lever about eight inches above step return. I know it is snow and rain water but why is the water level up and not leaking out? Any thoughts.

    • Davy Merino

      Hi Al, not sure about that one, normally a leaking pool stays a leaking pool, until something is fixed. Some leaks however, can seal up temporarily, when enough leaves and debris gets stuck in the hole or crack, it can plug it up, especially on a still, stagnant pool. Gurgling would indicated to me the step return draining out, but where, unless equipment is below the pool?

  34. Andrew gorman

    Good morning, purchased a new home three years a ago, a in ground pool was already there, roughly 10 years old, first year no problems any of the 4 seasons, second year i found i was adding water more often in summer and fall, not huge amounts but more then usual, the pool company i used when i asked replied does not seem like a unusual amount. Closed the pool end of October and in February realized level was two feet below skimmer, when i closed it was 3/4 up the skimmer. I added water then and in march and had the pool opened in April to look for leaks. monitored it and again did not go down a whole lot. Had a diver in twice to check for leaks and he did find one about a foot below water line, but again over summer had to keep adding more water then usual. had him back late September and he said he could not fin anything but around the main drains he made sure nothing leaking there. Closed pool late October and yesterday after the thaw pool was down again looks like two feet below but hard to tell as still some ice on top of cover. He had told me that if it does leak this winter that at least will know if it is the lines or liner as when closed there is no water in the lines as they are all winterized. very frustrated, just want to find issue. just Fyi i have one of those power covers that i close at nite in the spring/summer/fall to keep heat in and it is also my winter cover. Any suggestions??

    • Davy Merino

      Hi Andrew, yes we all those summers when we chase leaks – seems like you’ve had several! Have underwater lights been tested? Typically they leak out the conduit pipe, which may be about 2 ft below your deck. But if not the light – Vinyl Pools could leak around anywhere the liner was cut on purpose, this includes main drains, in-wall pool lights, step sections, skimmers, returns and other wall fittings. So those are always suspect, and close inspection of any gasketed steps or lights in this (2 ft down) area would be the first test. Often you will see bits of debris sucked up against a bad area of a gasket, or into a hole in the liner. Sometimes main drains have an automatic hydrostat relief valve installed, in the center of the main drain pot, with an o-ring that can deteriorate, but if the diver dye tested that then… He’s right about the pool lines, with exception to the main drain line, because they don’t dive in and plug the main drain during winterization. But you can rule out problems in the skimmer and return pipes. That could be another test, in season, close the valve at the pump and then dive down and plug the main drain pipe, and see if water loss stops. Your power cover needs water to support it, as you probably know – with heavy ice and snow, the track could come detached from the coping, and as you probably also know, it’s not recommended to move an auto cover unless the water level is correct.

  35. Davy, We have a 20’ x 40’ inground pool with a Vinyl liner & a Loop Loc mesh winter cover. Living in West Michigan, heavy snow loads can be a problem.

    When winterizing the pool a few months ago, the pool water level was lowered 4-6” below the skimmer. After a couple snowstorms last week, our winter cover collapsed into the pool on one side where 5 springs failed to hold the snow load. Using a wide shop broom and a roof rake, most of the snow has been removed from the winter cover. That’s when I noticed the (frozen) pool water level was down to 3 feet below the skimmer!

    Questions:
    1. How can the pool water level drop 2+ feet over the past 3 months?
    2. Should I add water to the pool now to raise the level to 4-6” below the skimmer to support the walls and winter cover?

    • Davy Merino

      Hi Thomas, the water loss is likely from the liner, or… from a break in the main drain pipe. It could also be a break in the pool light conduit, unless water level is below the light. It could also be a leak in the step section gaskets, but usually not. This is why the cover springs broke, because the water was so low. when the is mostly thawed, I would add 6 inches of water and watch how fast it drops, and if there any telltale signs, like water coming out of the ground in a particular area around the pool. If it is the drain pipe, it can be plugged, inside the drain, to stop water loss, until the pipe can be repaired, and it should be repaired, for good circulation. Also, the drain will have to be installed to meet new codes, requiring dual main drains, for safety. However, it’s likely the liner, a small rip, so don’t fret too much yet! Good Luck!

  36. My pool has a leak and I’m having to wait until spring to try a find it. How much water must remain in the pool before I run into liner tearing issues? Also, come spring, can I get the water clear (I don’t have a cover) with the water still below the skimmers? Thanks in advance!

    • Davy Merino

      Hi Dustin, as long as there is still 6″ or so of water covering the floor, the liner should stay tight or snug. If you have no main drain, and the water is below the skimmer, it’s hard to run the filter, but using a vacuum hose and hose adapter, you may be able to connect a vacuum, and leave the vacuum set-up, drawing water from the floor of the pool, thru the vac head. You may need to use teflon tape on the hose adapter, and push the vac hose onto the adapter very tightly, and it still may draw air. If so, setup a garden hose to trickle water into the skimmer, very slowly, or just enough as needed, to keep it from sucking air. Be sure the swivel end of the vac hose is on the vac head, or it will leak air, if connected to hose adapter.

  37. susan dockery

    winter my pool always goes low to where there are wrinkles in shallow end. New liner first of last spring. removed light..redid seals..the works. Yet it still has dropped already. after draining off safety cover it is dry so no leaks there.pressure test showed no leaks..we also lost water when pool was open.. We are totally needing advice…as is my pool guy!!

    • Davy Merino

      Hi Susan, so new liner, pool light conduit was sealed, pipes were pressure tested. OK, got it. Other possible light sources include the gaskets around step sections, wall inlet fittings (returns) and skimmers. I assume however, that the new liner included all new gaskets for light(s), returns, skimmer(s) and drain(s), and probably new faceplates too, which is a usual practice. Although any of those could be leaking around the gasket, from an uneven surface or loose faceplate. Look for any bits of debris stuck around all of the faceplates and step section plates, it’s a tell tale sign. Then those areas can be dye tested, after raising the water over the area, if needed. Finally, some main drains have an automatic hydrostatic relief valve, which is spring loaded and gasket sealed, this is screwed into the bottom port of the main drain pot. If the o-ring becomes upset or deteriorated, these can begin to leak. Most residential pools do not have automatic hydrostats, more of a commercial pool thing, but it’s a possibility, especially on vinyl pools perhaps. Good Luck!

  38. My gunite pool is leaking. The pool cover has been sucked in and the water is leaking down the hill behind the pool house. A giant stream. Did our pool company fail to winterize it properly? Do we have burst pipes? Thank you for any advice.

    • Davy Merino

      Hi Amy, so sorry to hear about this! Gunite pools do not normally leak thru the shell suddenly, so I would suspect a pipe leak or pool light leak as first guess. Pool lights are not commonly winterized, and they don’t normally form ‘giant streams’ of water, and only leak down to the pool light level, thru the light cord conduit. Main drains are normally winterized, by blowing air thru the pipe to force out all of the water, and then quickly closing the valve on the air filled line, to keep pool water from re-rentering the main drain pipe, like a finger on the end of a straw. However, there are all sorts of main drain plumbing configurations and many types of valves, so that method may not be always reliable.

      If your water level is very low, to the shallow end floor, below all of the other pipes (skimmer, returns), then it likely would be a main drain pipe breakage. Possibly freeze damage, but also possibly breakage from frost heave of the ground. In most cases freeze damage will spider web crack a pipe along long distances, but frost heave is more of a clean break of the pipe in one spot. It could also be a leaking hydrostat relief valve, some are spring load, and seal with a small o-ring, which can sometimes come out of the groove during vigorous blowing of the main drain. these are located in the main drain pot.

  39. Alexandra

    Hi Davey, this is the second year in a row that our above ground Pool empties “for no reason”. We had the liner replaced last summer and the summer before that as well. It’s hard to tell if we lost water this past summer after the liner was replaced because I would fill it routinely when the water was low (I thought it was due to evaporation or the kids splashing around). I did have a harder time than usual balancing and maintaining the pool this summer. When we did close it, around late Sept-early October, we did not see any problems. Slowly, by mid to end of November I noticed the water level going down. Now that all the snow has melted I was able to get a good look and noticed that there is hardly any water in it, just what has frozen over due to the extreme cold weather we had last week. We’ve taken water off of the cover since Oct but not enough to lower it that much and that fast. I’ve seen posts stating that the main drain should be checked but I don’t see a main drain on my Pool. I don’t even see an opening inside the Pool that would give access to a main drain either. Am I missing something? Replacing the liner each year costs almost $1000 each time and does not seem like an appropriate solution. My theory is that the foundation where the pool is was not prepped correctly and therefore not stable and the water may be leaking through the seams of the liner into the ground around the Pool. For now I am going to add more water into the pool so the liner does not collapse and hope that I can find a solution to this problem ASAP. Any suggestions or assistance from you, or anyone, would really be appreciated.

    • Davy Merino

      Hi Alexandra, sorry to hear about this trouble! For splashout and evaporation, in hot temps for sunny/windy pools, it can be up to 1/4″ per day, or about 1.75″ per week – more than that and I start to suspect a leak. Aboveground pools don’t have main drains, as they don’t usually have a deep end. Main drains (2 are now required) are used at the deepest spot of the deep end, almost exclusively on inground pools. Some A/G pools have what I call a LWS, or low water suction port, on the wall about 1/2 way down the wall, as a second pool outlet (in addition to the skimmer) to bring water to the pump. And of course A/G pools also have 1 or 2 wall returns, where the filtered water re-enters the pool. A/G don’t usually have thru-wall lights, but can. A/g pool leaks are thus usually easier to find, because the pipes (hoses) are exposed, and equipment drains down easily, and there are very few ‘incursions’ or holes cut in the liner, as potential leak sources. In your case, you will likely find a leak in the liner, at the level that the water is currently frozen at, or around there. When it thaws, put on waders and walk around slowly, inspecting the wall, at the water level. Larger holes may have debris stuck in them, a telltale sign. Smaller pinholes are harder to spot. Look closely at the skimmer area, where the wall panels normally join together, and may have sharp edges or screw heads. If your pool is completely empty, or has only a few inches of water, then the floor and intersection of wall/floor is your prime area. Find the hole(s) and patch the liner, probably no need for a new liner. If the foundation beneath is rough, with pebbles or rocks, that can cut the liner, under the weight of the water. You may have noticed that while swimming however, if the floor was not smooth. Adding more water is a good idea, to keep the liner from shrinking in the cold weather. See if you notice more moisture in the soil areas around the pool, that may provide a clue. If all of your plumbing lines are plugged, and the water level is below any such incursion anyway, and you didn’t pump out water with your cover pump, the liner likely has a hole, or possibly a failed seam, although that is more rare. Good Luck and hopes for a quick fix!

  40. Janice Schimpff

    Hi Dave we have a 16×32 inground pool . We bought the house 2 years ago and the only thing we know is that it was installed in 1971. We went to the company that installed it but the previous owners never went back to them for maintenance. We covered the pool in September but have no idea when we lost the water until the last snowstorm what should we do at this point besides trying to take the cover off at some point

    • Davy Merino

      Hi Janice, yes take the cover off the pool, and look for any tell tale signs, looking for any holes in the liner at the level of the water level. It could be a very small hole, or several small holes. It could also be the main drain pipe, broken at the level of the water level. In many parts of the country, main drains may not be fully winterized, maybe no need to, but with freezing temps for extended periods, frost can extend deep into the soil. Many light niche conduits also cracked this winter, if your leak is at the pool light level. See Cord Stoppers for light leak problems. Lots of pool problems this winter!

  41. Eileen Jeffrey

    We rebuilt our pool the liner is 3 seasons old this year we spent $1,500 to do the new tarp, that screws into the ground. This past snow storm, my husband heard a noise and the tarp flew off, the pool was completely empty, it NEVER had a leak, we are beside our selves as is our pool guy that closed it, he can’t understand why or what happened to the water. Now the liner is coming off the wall due to the pressure. Our pool guy stated maybe the liner split? I am sure its not guaranteed? it wasn’t leaking the summer we closed it. We spent $12,00 rebuilding it UGH

    • Davy Merino

      Hi Eileen, sorry to hear all of this. What may have happened is the liner developed a leak during winter, or the light or the main drain pipe began leaking – and this left the cover with no support – and then a heavy snow/ice storm put a lot of weight on the cover, ripping straps or springs all down two sides of the cover, causing it to fly off the pool. Or, the cover was just very loose and not attached well, and high winds got underneath. Either way, this winter put a lot of hurt on pools and pool covers, you are not alone. If your pool is completely empty, all the way to the deep end, that is a clue as to where the leak may be – either in the liner or the main drain pipe, at the level where the leak has ‘stabilized’. The liner may be able to be re-set, but when a liner sits in freezing temps without water, it shrinks a bit, and can be hard sometimes, to get a perfect fit again. Sorry again, good luck!

  42. Hey Davy. I have a 28000 gal vinyl liner in ground pool. The liner is 7 years old. I don’t think it was cared for very well by the previous owners. It’s faded, seems brittle and bead is pulling out of all four corners. Now a seam has ripped and pool is draining. I figure a liner replacement is called for. But my worry is damage to pool walls and the ground around the pool. What do I need to look for to be sure walls and ground are in good shape? Thanks

    • Davy Merino

      Hi John, good question. Inground vinyl liners are replaced with a prep process that includes – Drain pool, cut up old liner with razor knives and roll-up into 4′ long strips, remove from pool. Inspect walls and floors, and skimmers, drain, returns and liner track. Make any repairs or mods needed, then install the new liner….

      Walls are usually galvanized steel, and some rust is normal. Newer pools may have polymer plastic walls, and very old pools may have wood panels. Scrape off any rust and scale from the walls. Heavy rust can be painted with Rustoleum or similar coating to retard the rust and add a layer. Wall Foam is a liner accessory that can be used to cover rusty or rough walls, to protect the liner, add a small thermal benefit and a soft touch to the walls. Comes in a large roll, 42″ wide, 1/8″ thick, and is adhered to the wall with Spray Adhesive, and cut around wall returns and skimmer. Finally for wall prep, scrape off old gaskets and clean surfaces around skimmers and returns, and add duct tape on the vertical wall panel seams, first adding caulk sealant if there is any noticeable separation.

      For vinyl pool floor prep, it depends what type you have – concrete, vermiculite or sand. Many vinyl pools have a concrete hopper, or rectangle area around the main drain, and a concrete sand deep end sidewalls, slope and shallow end floor. Some pools are entirely sand bottom. For concrete or vermiculite bottoms, first clean the area and assess the needs, inspecting for cracks, divots, uneven surfaces or wavy joints between ‘floor panels’. with Vermiculite, you can easily fill in low spots, cracks and divots, but don’t raise the floor level much, unless you haven’t ordered the liner yet. In most cases the floor may just need a few touch-ups here and there, and be cleaned well to remove grit and pebbles, before the new liner is put in. Sand bottom pools are more work, the entire floor is sprayed wet and retroweled flat. Hiring workers that are handy with a trowel is a good idea for sand pool bottom pools.

      Don’t worry about the pool for now, just let it drain and when weather starts to warm up, uncover and get started. One more tip – leave most of the floor liner sections in place, until you are ready to work on the floor, just to keep it clean and protected. See this blog post about 5-step inground liner installation

  43. Hi,
    Our inground vinyl lined pool has leaked all the water out since we closed it in October. We know the liner had a leak in the corner of the deep end that we patched in the summer, and we are planning to replace the liner in the spring. Should we worry about patching and refilling the pool before spring? Our pool is 10 years old and sits on a hill with a retaining wall behind it. Thanks!

    • Davy Merino

      Hi Casey, apologies for the delay in response, been on holiday… there is a slight risk of the walls collapsing, without water in the pool – however, that requires several factors that are likely not in play, since the pool is on a hill and there is a retaining wall. it takes a large amount of pressure, from moving soils or hydrostatic (water) pressure, to move vinyl pool walls. If your pool has a sand bottom, (not especially common), leaving it empty would/could erode the floor surfaces, requiring reshaping when the new liner is installed, but your floor is likely concrete/vermiculite. In your case, it would likely be no problem to leave the pool empty all winter, but plan on an early liner install, before heavy spring rain comes… let me know if you have other questions!

  44. Richard Ross

    Hi, I have a cement/ gunite pool, approx 20,000 gallons. I just had it resurfaced, they refilled the pool on Friday and we have lost approx 5000 gallons since then. I assume through the hydro static relief valve. They are diagnosing as I type but my question is should I be concerned with the ground underneath the pool if it has absorbed 5000 gallons over 2 days?

    • Davy Merino

      Hi Rich – yes, probably the hydrostatic relief valve… and no, I wouldn’t worry about the water in the ground, it should be absorbed into the ground without problems.

  45. I had inground pool with autofill and auto cover. I turned autofill about four weeks ago and now noticed that my pool dropped about 4 inches. At some point my cover pump stopped working and i collect quite amount of water. Is it possible that water on cover pushed out water inside a pool or 4 inches is a lot.

    • Davy Merino

      Hi Max, yes – water on the pool cover can push out water in the pool in some cases, but not over the top of the pool coping, but could thru the skimmer. Or the pool could have a leak in the light, or drain or other places. Or, your cover pump could be pumping out pool water, if there is a hole in the cover, close to where the pump is located.

  46. Hi Davy,
    Our gunite pool has been closed for the winter for about a month now, and the water level has steadily been creeping down about an inch or so per day to the point that the shallow end of the pool (down to about 4 feet) is now completely drained (note I do not typically cover the pool for the winter, so I had a good view of this happening). We had a similar issue last winter and about once a month I refilled from the hose to to keep the pool at least partially filled. For whatever reason the leaking significantly slowed down (if not stopped) once we reopened the pool in the spring. I suspected the issue might be the deep end drain hydrostatic relief valve, bought a replacement, but couldn’t hold my breath long enough to get to it to replace. Now that the pool’s been closed again the leak is definitely back at full strength.

    So anyways, my question– Do you see any realistic problems with simply allowing the leak to fully drain the pool (assuming that’s what will happen if allowed to run its course without refilling from the hose)? I’d like to be able to leave it empty so that i can change the relief valve and acid wash the pool (it needs it) come spring, and all else being I’d just rather not have to break out the hose during the dead of winter to periodically refill with our well water (especially since I can’t run the filter).

    I understand the big concern generally with leaving a gunite pool empty is that hydrostatic pressure could push the pool up out of the ground, but my thinking is 1) if there was existing hydrostatic pressure at some point the deep end would simply stop leaking, 2) if it got rainy enough in early spring to build up hydrostatic pressure the rain should similar refill the pool, and 3) where we live is fairly hilly and the pool deck is 10 feet or more above other parts of our property where water should generally drain, so hydrostatic pressure probably is never going to be an issue in any case. So anyways, sorry for the longwinded explanation but just wondering if I’m thinking about this the right way or if you can think of any other potential problems I might be missing (possibly issues with moisture/freezing at the bottom of the otherwise empty pool?).

    Thanks much!

    • Davy Merino

      Hi Matt, aside from the hydrostatic pressure problem (that you may not have), another concern is that the pool plaster and grout may suffer some damage or staining from being drained. If it is old plaster anyway – then maybe not much of a problem. Your last sentence may be important, as water in the ground that freezes will expand and put pressure on the pool and deck – probably nothing will happen, but possibly could. another option may be to let it drain out completely, replace the hydrostat, and inspect well for any cracks around the deep end and drain, acid wash it (in winter), and then refill it. even better may be to use a small submersible pump to pump out the water, more rapidly – and, pumping the water away from the pool, rather than letting it drain underneath the pool. You could probably leave it empty for winter, but much less risky to fill it up at least 25% again, after repairs. If you do leave it empty, open up the floor hydrostats, the one in the drain, and at least one other one further up towards the shallow end (they are plastered in place – chip out the plaster and use straight pliers to unthread the plug – replacements are usually a Hayward SP1022B…

  47. Hi! So we closed the pool about 6 weeks ago. Today I noticed that the water level seemed really low. We drained it about 4 inches below the skimmer. It now seems to be well over a foot below. When looking at my pipes I noticed that the main drain wasn’t turned to off. Could that be the reason I have lost water? Any steps to take if that is the case? Should I put water in?

    • Davy Merino

      Hi Scott, when a winterized pool is leaking below the skimmer, under the cover, it’s usually:
      1. leaking main drain, pipe, or the gasket for vinyl pools
      2. leaking pool light conduit, and/or the gasket for vinyl pools
      3. leaking pool liner (holes) or cracks in concrete pools
      4. leaking return line plugs, or gasket on vinyl pools

      Assuming that your filter system is not below the water level, then it could also be leaky plugs. You may have had a leak for some time, and just not realized it until you closed. The main drain valve position is likely not the problem, unless your pump is below water level. Let it stabilize, remove the cover if needed, and try to find

  48. Our pool level has dropped dramatically since closing in early October. We have an automatic cover – it is sagging quite a bit. We thought we may have a leak this summer, but we just put water in it knowing that we’d need to replace the liner in the spring. Do we risk damage to our automatic cover if the water level continues to drop this winter (sagging and added eight of snow, ice, and leaves)? If so, what should we do to remedy this until we are able to replace the liner (and determine the cause of the leak) in the spring?

    • Davy Merino

      Hi Emily – yes, it can damage the auto cover if there is not enough water to support the cover and any rain/snow. It can pull the tracks out, or rip the fabric or tear the scrim (edge). It can also be damaged by rolling up the cover without good water level. So it’s quite important. Many people in my area with auto covers, use a mesh safety cover during winter, and keep the more expensive auto cover rolled up during winter. I’d fill the pool up to the bottom of the tile, and carefully roll up the cover and try to find the leak. It may be right around the level it’s at now – returns, light conduit, step trim – look for small debris stuck into any areas at the water level now, that’s often a telltale sign of a leak.

  49. Jackie nenni

    Have a brand new above ground pool.the skimmer cover looks like it’s not sealed because I see drops of weather coming out of the skimmer on the out side of the pool .how do I stop it . The water is now almost below the skimmer.is there a way to seal this better?

    • Davy Merino

      Hi Jackie, aboveground skimmers have 3 gaskets, on on the outside of the pool wall and two on the inside of the pool wall, one under the liner and one on top of the liner. If water is leaking on the outside of the pool wall, the outside gasket is bad, or the screws are loose. Remove the front faceplate by removing the 10 or 12 screws, and then you should see the 4 round head screws that secure the skimmer tightly to the pool wall. Since the pool is new, the gasket is probably good, just the screws are loose. Tighten the up, replace the faceplate and raise the water level to test. If it still leaks, order a set of skimmer gaskets and replace. Check that the wall is not bent at the sealing point, crimps or bends in the steel wall make it harder to make a good seal. Good luck!

  50. Beth Schmidbauer

    I have an above ground pool and patched a leak in the liner floor prior to closing our pool. We plan on replacing the liner in the spring. We mistakenly drained all the water out of the pool at the end of the season and covered it. We had a huge rainstorm over the weekend and the cover caved in and one side of the pool collapsed. My husband was able to fix the wall and reattach the liner. We refilled the pool but overnight half the water has drained out!! What do we do now??

    • Davy Merino

      Hi beth, if you can swing it now, I would do the new liner now – like this weekend or the next. If not, drain the pool fully and patch up the liner holes again with large heavy patches, or use Anderson Leak Sealer or EZ Patch 28 – which squeeze out of toothpaste style tubes – the previous patch may be leaking or there may be other leaks. Find them all and refill and recover the pool, and that may hold you over winter…

  51. Hey, I have an above ground pool, 15 foot round. I dropped the level below the skimmer when I closed. I looked out today and the water level was about a foot below where it had been when I closed. I had a leak in the one gasket for the inflow, but it’s below that level. None of the ground around the pool is boggy that I can detect (there is an area with a deck that I can’t check). Is it possible it’s evaporated off? It’s been exceptionally warm since I closed and when I checked the water this past weekend it was like opening is a shower stall when I peeled the cover back. Any thoughts?

    • Davy Merino

      Hi shouldn’t be evaporation, it’s covered, right? If you have been pumping rain water, and there are holes in the cover, you could pump pool water out thru holes (use an upside down frisbee to remedy). Otherwise it could be a leak, and a leak in a winterized above ground pool, below the skimmer, is cause for concern. Concern that the cover will fall in, or tear, or concern that the liner will be ruined, or worst case, that a large ice sheet will form, and the pool will leak out, below the ice sheet, and the ice sheet will slip, fall and damage the pool :-0 So it should be looked into, pull the cover halfway off and inspect the pool return, and any other gasketed holes in the pool. They can be leaking between the vinyl liner and the pool wall, or sometimes drip down the outside of the wall. Then look for any vinyl rips or tears, they sometimes have debris stuck in them, sucked into the tear. Shouldnt be too hard to find on a 15′ round! Hope not…

  52. Hi, I have a 15 x 26 oval OGP with vinyl liner and closed it for the winter with a solid cover. The water level has dropped 3/4″ over 4 days. I can tell this by looking at the skimmer cover. I can see the water level through this semi-transparent skimmer cover and marked it with a Sharpie. I figured this to be about 39 gallons per day.I live in Massachusetts. I have couple questions:
    1.) If I remove the winter cover, do you think there is a good chance I could see the hole at this leak rate?
    2.) If I choose not to remove cover, can I just fill the pool occasionally until it freezes and find the leak in the spring without damaging the pool?

    Thanks for any advice.

    Mark in Massachusetts

    • Davy Merino

      Hi Mark, i would carefully watch the leak, and see if it stabilizes in another few days. If it continues to drop below the skimmer, several inches, I would remove the cover to try and patch it. The pool won’t freeze solid from top to bottom, so the largest fear :-0 is that a thick ice sheet will form across the top of the water, and then the pool will leak below the ice sheet, and then BOOM! the very heavy 6-8″ ice sheet falls or tilts in such a way as to damage the pool or liner. So, if the leak is up around the skimmer or return, just let it drop to that level and you’ll be fine, or you could pull back the cover and fix it now, your call. But if the leak is on the floor, or lower on the wall, it should be fixed before winter sets in.

  53. We have an above ground pool. A few weeks ago my wife notice it was leaking from somewhere because the ground was wet below the skimmer and the water was lowering. We tried looking for the leak but have not been able to find it. We thought it could be the skimmer so we drained the water below the skimmer to see if it would still keep lowering. We think it could still be leaking because the ground below the skimmer seems to still be wet but the water level doesn’t appear to be dropping. If it is still dropping its doing so very slowly where after about a week we still cant tell if its falling or not. However we can still see that the ground is still wet. Its not wet all around the pool, just at the bottom below the skimmer. Its the end of the season now and we’d like to close the pool, and hopefully next spring figure out where the leak could be from? Not sure if this would be a good idea, or if we need to figure out the leak first. I’m just looking for some advice on what the best way to handle something like this would be? Thanks in advance.

    • Davy Merino

      Hi Sy;

      The leak very probably is in the gaskets behind the skimmer faceplate. I would order new faceplate and gasket set (2) for your particular skimmer (they are all different), and replace them before closing, fill the pool back up first and test it out. It could also be the liner of course, but it would be a pretty good sized and noticeable hole to lose that much water. Most likely the water is leaking down in between the wall and the liner, and running under the pool wall, making the ground wet outside the pool.

  54. Over the winter the main drain in my pool was leaking due to an accessible crack in the pvc drain pipe. I taped the crack (enough to reduce the leak) and filled the pool. With pool now open for the season, I am wondering the best way to temporarily seal the main drain during the repair. There are 12″ rubber mats that go over the drain covers but I thought diving down and temporarily plugging the drain would be more effective. Any thoughts on best solution to seal drain during repair? Thanks.

    • Hi There, yes, diving down there with a screwdriver and mask, remove the drain cover screws. After a few breaths of air, you can plug the pipe with a #10 or #11 tapered expansion plug. The hole is usually on the side of the drain pot. That will stop any water flow from the pool, assuming your break in the line is below water level. Be careful not to turn on the pump with the plug in, unless you are sure enough the plug is large enough that it won’t get sucked in.

      Plugging the main drain is also a way to determine if the main drain is leaking or not, without pressure testing. And, when main drain lines crack, and the cost to repair is prohibitive, some people may plug a main drain line permanently – for this a glued PVC plug would be a better choice. And, if you do abandon the main drain, you will need to take some measures to improve filtration, circulation and/or sanitation, to compensate for the reduced deep end suction into the filter.

  55. My in-ground gunite pool was losing practically all water (about 30,000) within 2 months. I have to add water … BUT! Now the opposite happens – the level of water under the cover RISES! We had some rains lately (Eastern PA), so how to explain? Ground waters are getting into the pool? Could not find anything on the web …
    Tanks

    • Davy Merino

      Hi Val, some pools have an automatic hydrostatic relief valve in the main drain pot, to allow ground water under high pressure, from a high water table, to enter the pool. But only if it’s spring loaded and automatic, other types of hydrostat valves have to be manually opened. Another possibility is that the very high water table is leaking in through a crack in or around the skimmer, or possibly even being sucked into a suction pipe that is cracked underground. Or it’s raining a lot at night, when you don’t notice it? It’s definitely a rare problem to have, so I’m just grasping here for ideas…

  56. Hi, So my 15ft round pool lost all of its water during the winter, I didn’t think there was anything I could do short of continuously putting water in so I just let it drain… I have a idea where the leak is and will be easy to patch since there is only about an inch or so of water in it. My concern is the integrity of the pool since thousands of gallons of water leaked into the ground below. What are your thoughts?

    • Hi Lee, Good question. sometimes when thousands of gallons leak out one side of the pool, the ground softens and slumps, resulting in that area of the pool dropping an inch or so. Good A/G construction practices can prevent it, with french drains and gravel installed to remove such water away from the pool. Lots of ground water around the pool can also rust the bottom ring or bottom portions of the wall, but not a one time event, takes years to breakdown the coatings. You will probably be OK – you’ll know for sure after you refill the pool, and look at the water level on that side of the pool, if it is higher than the rest of the pool, that means the pool has settled a bit. Then, you’d just have to live with it, I suppose.

  57. We have a 18×36 inground pool (vinyl) and checked pool in January everything looked fine checked again then in February water was down to third step. now no water in shallow end

    We’ve had the pool since 1987 never had any trouble. In July of 2015 put new liner in. Help!

    Michelle

    • Hi – yikes! I know this is horrifying, but try not to stress to much. If the water level has dropped below all ‘cuts on purpose’ to the liner (steps, returns, skimmer, light…) then that only leaves the main drain as a possible leaker, or the vinyl liner. That’s good news – you’ve ruled out a lot of mystery. Pull the cover off now, if you haven’t already, and take a good look. You may find a dead animal (!), or maybe a small pump that a helpful spouse hooked up to lower the water level. Barring that, you would next inspect the pool liner, very closely, at or just above the water level. Using an inflatable boat (or wetsuit) may be needed. Look closely for anything that looks like a hole, they often have debris (small grasses) stuck into the hole, being sucked in to the hole. At the rate you describe the leak, it should be visible tear or hole. If you don’t find one, check again, or have a different set of eyes look closely. There may be more than one leak, or hole in the vinyl. Now, if you look closely twice or thrice, and see no hole, then you can assume that it may be the main drain. Could be the pipe, or it could be the gaskets that seal the liner to the main drain. It could also be a leaking hydrostatic relief valve, sometimes placed inside (directly in the bottom center) of the main drain pot. The gaskets and drain ring (the one with 8 screws around it) can be dye tested with food coloring, to see if that is the leak, although clear water is needed – which may require filling and starting the pool, to find and fix the leak. Alternatively, you could just drain the pool and replace the main drain gaskets. If the drain ring is leaking, you may have some recourse with the person who installed the liner, but only if they are super-nice guys. If the pipe is leaking on the main drain, you can plug the line, and close the valve on the other end, and see if the water level holds, and stops leaking. If so, you could a). Try Fix-A-Leak, pressurizing the line to fill the cracks, or b) repair or replace the line, or c). abandon the line, and use a pool cleaner more often to help circulation. But – it’s likely not the pipe (most rare). Most likely the drain or the liner, or a pool light or low water suction line at or just above the stabilized water level. Good Luck – let me know if you have more questions or information to share.

  58. Mindy DOBBINS

    I have a 21 foot round pool and when I closed it it was fine but I didn’t drain the water off the winter cover and my pool water levels dropped about two or two and a half feet deep. I was wondering do you think I have a hole in the liner or is it from all the water pushed over the side cuz there’s air behind the liner I don’t think there’s a hole

    • Yes, your theory sounds correct. When the pool cover fills up with water very deeply, it can force pool water to drizzle over the edge of the pool wall. Or if you have a hole in the pool cover, and when you were pumping off the pool cover, you may have also been pumping out some of the pool water, along with the cover water. Take a good around the edges, and if you don’t see anything that looks like a hole (many times there is debris stuck in the hole), then you’re probably fine. Go ahead and fill up the pool, and if you do discover a leak later, just use some vinyl patch, or Anderson Flexible Sealer

  59. Joanne Beesley

    I have a 16×32 inground (vinyl) checked to see how water was doing! NO WATER in the shallow end! Don’t see a rip or tear! What is the best way to find the leak!

    • Davy Merino

      Hi Joanne – Yikes!

      Let’s pull off the cover completely, if you haven’t already. Carefully enter the pool, wearing some non-skid shoes, and carefully inspect the pool at the water line. First, to see if the water level is at or near a cut in the liner made on purpose – such as steps, returns, lights, etc. If it’s way below anything like that, then inspect closely around the water level in the pool (you can use an inflatable boat, or put on a wet suit). Looking for a hole in the liner that you can patch. Corners or angles in the liner are often the first suspects.

      if there is no hole in the liner, at all. It looks perfect… then, you may consider some other sources. Usually only two, if the pool lines were plugged for winterization. Those two are the main drain and the (possibly) hydrostatic relief valve in the drain pot. The main drain pipe could be broken, but that’s actually pretty rare, so don’t get worried until you know. It could also be the main drain ring, the sealing ring which has a gasket…, or sometimes builders use automatic hydrostatic relief valves, which have an o-ring, and if something is stuck between the cap and o-ring, small stick for instance, then it can leak.

      Another source of such a leak is mistakes made when lowering the pool water level, and overpumping it – for those with mesh safety covers, and the water gets too high. Or, for solid floating pool covers, if there are holes in the cover, and your cover pump is set near the holes, it can pump pool water thru the holes, and out the pump discharge hose, lowering the water level.

  60. Sean Smith

    I have an above ground pool that leaked last year for the first time just be low the skimmer. So before I opened it last summer I change the gasket behind the skimmer. I thought this would fix the problem but again the pole level is lower. Should I check for leaks in the liner or change the whole plastic skimmer box completely? Thank you for any advice

    • Hi Sean, I assume that your pool is just now being opened. If your pool cover had any small holes in it, your cover pump could have lowered your pool water level, by pumping water thru the holes in hte cover… but assuming not, then I would first inspect closely around the level of the water, before filling, looking for any holes in the vinyl, or any debris stuck in a hole, which gets sucked in there by the water. You can then use food coloring to dye test (might need to add an inch of water first). You can also dye test the skimmer faceplate, and also the return and light rings, if applicable. No need to change the hole skimmer, unless parts are cracked or missing. Skimmer faceplates, by the way – must be tightened Very Tight! Use a large #3 Phillips head to really crank the screws down until you hear the plastic creak. Also, two gaskets should be used, one behind the liner against the wall, and one on top of the liner, underneath the faceplate.

  61. Judy Primavera

    Hi, I have a semi-inground pool with salt-water system. I woke up yesterday to find the pool cover lying in the almost completely empty pool. I think the pool cover siphon drained it overnight when the cover straps tore. My son climbed in to remove the large blocks of ice from the cover and we siphoned off the rest of the water. I added water (almost at the half way mark now) and was able to repair the cover straps. Can I add shock and ph without attaching the pump? I’m not able to take it out of storage without my husband’s help.

    • Hi; yes you can add chemicals without the pump running. Dissolve your ph chemical in a bucket of water, and pour around the edge. Rinse the bucket clean, fill with water again, and then add granular chlorine and dissolve it by stirring for 1 minute. Pour the solution into the pool, being careful not to let undissolved granules fall in as the bucket empties. After adding chemicals, use your pool brush to distribute by creating some circulation with the brush.

  62. We have an inground pool. the saftey cover has dropped into the pool at one section. We cannot get out the pool due to snow levels around the pool to look under it (and I am not sure how we would be able to see anyway). Mid summer we had a leak crew come out and the plugged all the leaks in the pool and the water level remain stable for 2 months till we closed. Now this. There is nothing we can do now till May when we open correct?

    • Hi Beth, Safety covers are not usually affected by water level in the pool, unless the water level drops lower than 18″ from the cover – in such cases, the water level no longer supports the cover, and when wet/heavy snow and ice falls, the weight can bend cover springs, or tear cover straps. In your case, if the water level has dropped to a very low point, you can add water to the pool from a hose, to raise the water level again. If you can remove some of the snow, you can look under the cover, or cup your hands around your face and put your nose right up to the cover and you can see thru a mesh cover, to check water level. It could be possible that the water level is normal, and what you are seeing is the cover stuck to the ice and being pulled/stretched down. Let me know if you have other questions. When the ice thaws enough, pull the cover back tightly over the pool, and if there has been water loss, add water to fill. If it drains again, remove the cover and look around the water line (where the water level stabilizes) for failed patches, obvious holes, or places where you see debris stuck to the liner (stuck in a hole).

  63. I came home yesterday to find our solid inground pool cover had fallen in the pool but more importantly, the water has leaked out SOMEWHERE down to about a few feet in the deep end. We have a vinyl cover that we planned to replace in 2018 but which we thought still had some life in it. My major concern is whether the ground around the pool is safe. Is there a chance for a sink hole or anything since all the water has clearly seeped into the ground? Also, what could have caused this so suddenly and dramatically.

    • Hi; likely no problem with the ground water, no worries there. Two things could have caused this, maybe 3. first is a wild animal that fell in the pool, trashed the cover and ripped the pool liner trying to get out (he may still be in the pool(!). #2 – old liners can sometimes just ‘snap’, because they become so brittle, that they just rip, during one cold day. #3, a pool cover pump, used for solid inground pool covers, could have been placed in an area of the pool cover which had a hole – and then the pump began pumping out pool water, through the hole in the cover, until the pool was so low, that the cover fell in the pool.

  64. Kathy Kirane

    Hi, I have an above ground pool, one of the rods popped through the liner making a perfect round role, little like a half dollar, is this fixable, another issue we had a gopher go under the liner about two years ago, should we try to work our his tunnel damage or can that hurt the liner, pool only 4 years old..

    • Hi Kathy, the small hole sounds patchable, with a regular vinyl patch kit. Doing it on both sides of the hole will make it stronger, to prevent further rupture (hopefully!). You can also wrap the rod end with duct tape or something to pad it a little, or cover the sharp edge of the rod. For the gopher tunnels, I assume that you have a sand floor under the vinyl. You can smooth out the edges of the tunnel using a rounded blunt instrument. I like to use a 3-4 ft length of PVC pipe, attached to a 2″ Tee fitting, and use it as a ‘sand hammer’, while standing in the pool and wearing a swim mask, to reduce the edges of sand divots (or gopher tunnels!).

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