If you have a Diatomaceous Earth (DE) pool filter, congratulations. There is no better type of pool filter to have working to keep your water clean and healthy. But D.E. filters require a little more maintenance than sand or cartridge filters. This is due to their more complicated design, with twice the number of internal parts as compared to sand or cartridge. They are also more complicated in operation, requiring the operator to maintain the ‘cake’ of filter powder on the grids, and flush out the grids with a hose at least once per year.
Let’s take a look at some common DE pool filter repairs, all of which you can do yourself, with the help of our pool filter parts.
DE Pool Filter Repairs: Leaks
Leaking Clamp Band
The first DE pool filter repair is one of the most common, a leaking clamp band. Start with a clean and lubed belly band o-ring. Dirty, dry o-rings don’t seal very well. When tightening your clamp band, make sure it’s centered over both tank halves, and tighten the clamp with a socket wrench, until the springs touch. If the clamp band leaks, shut off the pump right away, loosen and reposition the clamp band. Tighten up again, using the handle of the socket wrench, or other heavy tool, to tap the clamp band around the edges, as you tighten. This tapping will help to seat the clamp over the tank halves. If it still leaks, inspect the o-ring and clamp band or filter tank halves for damage.
Leaking Drain Plug
The drain plug for your filter tank should be wrapped 3x with Teflon tape (wrap the threads in a clockwise direction). Some DE filters also have a large o-ring on the drain plug. Using a pool lube will prevent it from dry rotting, and can help in sealing up a leaking drain plug.
Leaking Air Relief
The air bleeder on top of the filter tank (sometimes automatic, sometimes manual), is meant to release air from the tank during start-up. It’s an important safety measure to open it before turning the filter pump back on. If it drips water, there is usually an o-ring that is missing from the air relief stem. If the assembly is cracked around the pressure gauge, this is usually caused by having years of Teflon tape built up on the gauge, expanding and cracking the plastic housing. Super glue can sometimes effectively repair this little crack. Squirt in while open, then unthread the pressure gauge.
Leaking Valve
The filter valve on a DE filter is unique, and different from side mounted sand filter valves. If your valve is leaking, either around the lid, around the handle, or where the pipes come in and out of the valve, there is probably a need for some valve parts (not considered filter parts). Water leaking out of the backwash port while the valve is in the filter position, would indicate a need for a new spider gasket, or piston o-rings, if you have a push-pull slide valve.
DE Leaking from Manifold
In the video, Rob replaces the DE filter manifold on cousin Joe’s Pentair DE pool filter. The manifold had cracked around the air bleeder assembly, probably from running too long at high pressure, or a return side valve could have been closed, causing a water hammer effect to crack the plastic. Manifolds can also crack if the grid assembly falls over hard while it’s out of the filter tank being cleaned. A common cause of DE in the pool is a missing or damaged manifold air bleeder ‘sock’ or ‘screen’, which are used as strainers for the air bleeder on top of the manifold.
DE Leaking from Grids
Over time, DE grids will develop small holes in the fabric, or the stitching on the grids can begin to unravel. A loose grid assembly, with the thru-bolts not fully tightened, or from incorrectly spaced grids, can allow DE powder to bypass through small holes where the grid inserts into the manifold. Chemical damage can burn holes through the fabric, or a severe water hammer effect can crush grids. Grids can also be crushed if you store them in the garage during winter, from an SUV! You can usually find holes in grids by hosing them clean and inspecting thoroughly. DE grids with holes or other damage can be replaced individually, or you can buy the entire grid set.
DE Leaking from Standpipe
Most DE filters have a PVC standpipe, where the manifold connects, and on top of the standpipe is a small o-ring to seal-up the manifold to the standpipe. If this o-ring goes missing or breaks, you can pass small amounts of DE and dirt back into the pool.
DE Passing Through Valve
If DE powder passes through to the pool mainly when you add new DE powder, this could indicate a problem with the gaskets or o-ring inside of your filter valve (Multiport or Slide valve for backwashing), which also means that your filter valve is bypassing some water without being filtered.
DE Around the Main Drain
If you notice DE powder spilling out of your skimmers, or a cloud of powder around the main drain, this means that the filter is back-draining through the pump, and spilling DE powder back into the pool. FInding the air leak on the filter, or installing a check valve will fix this problem, and keep the water in the pump and filter, so it doesn’t drain out through the skimmers or drain.
High Filter Pressure
You’ve backwashed and added new DE powder, but the filter pressure stays high, or it drops only for a few hours. First, check that the pressure gauge is accurate and not stuck. Also confirm that nothing downstream of the filter is causing the high pressure, like a closed valve or a pipe obstruction.
Next, pull out the grid assembly and hose off completely. Reassemble and add the recommended amount of DE for your pool filter, which is usually 1lb of DE for each 5 sq. ft. of filter surface area (a 1 lb. measure for DE powder is the size of a 1 lb coffee can). If you still have the issue, clean the filter grids with a DE filter cleaner, to remove oils and minerals that are clogging the grids.
Hi, I have a Pentair FNS Plus 48. I’ve cleaned the filtering grids and recharged the system with DE. Starting pressure is 28 psi. I’ve read that most people with the same type of filter normally start at least 10 psi lower. What should I check for possible causes of the high psi?
Hi Kevin, yes 28 psi is high starting pressure. High pressure indicates an obstruction, “on the pressure side” of the system, or after the pump. It could be the filter grids, clogged with oils or scale. OR it could be not enough DE powder. Or it could be that the pump is oversized for the filter and system, and that is the cause of the high pressure. It could be after the filter, such as a heater that is clogged up with lime deposits, or restrictive things like chlorinators or small valves. Or closed valves. Or an actual clog in the return line or at one of the 90’s, or a plug in the wall fitting return(s)… so you will check from the filter, to the pool, for something that is causing the high pressure. If you have a multiport valve, put it on recirculate position and check filter psi… if much lower psi on recirc position, the problem may be in the filter, and not after the filter.
Hayward DE filter replaced entire unit now valve at bottom of filter will not stop leaking once it was opened to backwash. Have tried to turn shutoff valve handle as far as possible still leaking.
Gini, there may be some grit or dirt around the ball of the valve. It may seal if you open up the union nut and clean off the insides. Or you can remove the valve and replace it with a threaded plug with o-ring, Hayward SPX1022C. Or replace the valve, Hayward SPX0723
Hello,
I have DE Filter and noticed its leaking from the bottom of the tank. I don’t see its leaking from the plug. Its pretty much leaking at the base of the filter tank. Please could tell me the reason? Is the tank is cracked? do I need a new filter or can it be fixed? Please let me know. Thank you
Hello, sometimes the tank clamps will slowly dribble and run down the side and drip off the bottom. If that is not the case, and no water around the side or around the plug then it could be a crack in the tank, which is not usually fixable, although you can try to patch from the inside of the tank, with a JB Weld type epoxy, but it usually does not hold. If it is a stainless steel tank, an ARC welder may be able to repair. It could also be condensation however, when the water temp is much colder than the outside air, the tank may ‘sweat’ water and drip off the bottom. Or if the tank is located in a cooler, or air conditioned room, it could be condensation. ONly way to tell is to open it up, clean off the filter and remove to inspect. Oh, and some DE filters have an underdrain assembly that connects on the bottom center of the tank, with a gasketed union assembly. If so, this could be the cause of the leak, a bad gasket or loose locknut.
It looks like I need to replace the drain plug on my Hayward DE 2400 filter. After turning pump off, I will release the air pressure before removing the plug. As I understand it, I just need some Teflon tape to wrap around new plug. I am noticing some “stuff” around the current plug, but just checking if I need to do anything else besides maybe add some magic lube to the o-ring. Anything I should remember before or after changing plug?
Hello Alfred, nothing special, lube the o-ring as you mention, that should seal it up. If the o-ring does not make a tight seal, some Teflon tape or silicone sealant can also be used on the threads. If you need to replace the plug, you can use Hayward SP1022C, or our item W1105, just $5.
Thanks! Part worked like a charm, but was probably just the o-ring. Hoping it hols up, but no leaks after an hour. Just like it was suggested wrapped in Teflon tape 3-4 times and a little bit of magic lube.
I am having a problem with my pump sucking air when I run it through the DE filter. It works great when I use recycle. I have cleaned the DE GRID,but didn’t take the grids apart. My pressure runs around 30 PSI, I don’t see any leaks around the filter.
Hi Kevin, when running water thru the grids, the pressure is higher, the pump has to work harder, so air intake is more common, because the pump is pulling harder. The most common air intake spots are the pump lid and the pipe coming into the pump. Lube the pump lid oring and crank the lid down very tightly, and for the threaded inlet pipe, you can patch it with a Pool Putty, leaving the pump running for 24 hours while it the putty dries. Air can also come from leaky skimmer or drain valves, or from a vortex swirl in the skimmers.
Hi i need some help, i have a new pentair quad de 60sqft and it keeps tearing up the filter cartridges ballooned pleats and breaking of the cartridge plastic molding while having a 6-8 psi never ten. We’ve checked flow rate compatibility, air leakage before an after the pump. 2 sets of filters already this summer and it’s only July.
Hi John, that sounds like the filter is plumbed backwards, with the plumbing attached to the wrong in/out ports of the filter?
I too am plagued with a DE leak. The DE settles on the bottom near the return jets. I replaced the spider gasket, cleaned and inspected the grids. I found 2 small holes at the top of 2 grids and I epoxy covered both. I reloaded the DE and WHAM! more DE in the pool.
By the way, I have 2 different DE scoops, one blue and one orange. Each holds a different amount of DE. The blue one holds about 1/4 less.
Wham! 🙂 the most common places for a DE leak are 1) holes in grids 2) missing manifold air relief strainer or sock, 3) cracked manifold 4) missing standpipe o-ring, 5) loose filter assembly – thru bolts not squeezing grids up into manifold, exposing gaps at the top of grid, and 6) air leak on filter allowing de to flow back into pool, thru pump, down to skimmer or main drain, 7) multiport valve or push-pull valve issues.
Would a cracked manifold lead to increase pressure? My pool is crystal clear (finally). I gave the filter a thorough cleaning put all together added DE. My starting pressure was 10, but over one night climbed to 25. I did notice the manifold was cracked but I thought that would be a DE issue in the pool not a pressure one.
Shawn, that should not be the cause. a cracked manifold could let some DE powder into the pool, but should not raise filter pressure. Unless, it completely cracked releasing large pieces of pipe clogging plastic, and a lot of DE into the pool. If the pool is clear, did you put enough DE powder in the filter? 1 lb of DE powder should be 32 oz dry measure, not 16 oz (in case you did not know), because of it’s fluffyness! Try to bump the filter (quick, 15-sec backwash), and notice the pressure drop, see if it stays low? If not, fully backwash and recharge. If it happens again, open the tank again and hose off clean and inspect. You can patch manifold cracks (sometimes successfully), with superglue or JB Weld.
Hey there,
I have a small crack in my manifold and I’m waiting on a replacement part.
There is a temporary “fix” to the cracked manifold.
I’m looking to start a 3 day treatment to balance my water. Will the chemicals be affected by this repair?
Nah, from the glue or epoxy used to seal the crack? No problem, go ahead on the water treatment.
Hello,
I just assembled my Nautilus NS72 pool filter for start up. When I initially turn the pump on I can hear water filling the filter but when it fills I get a steady stream of water from pressure relief valve.
Hi Tom, that’s good that means all the air has been bled out of the filter tank. Once water is spraying, you can close the air bleeder valve or thumb screw.
Thank you for the detailed response, you are an awesome person for taking the time to go through these questions and providing answers.
To your response, I will do that, is the multiport difficult to disassemble? I’m semi handy, but would prefer to steer clear of a complicated rebuild that will cost me a few hundred in the long run anyway.
Also,for what it’s worth, when I replaced the filter cartridges the stand pipe separated from the bottom manifold. I had a hard time getting the stand pipe to reseat, could it be a pinched o-ring there?
Hi John, thanks. When you say standpipe, do you mean the bottom Pipe Outlet the black elbow under the manifold, or do you mean the Air Bleed Tube Assembly that runs thru the center, vertically top to bottom? Either way, in any case, both would cause leaking and is probably the cause of your misery. The Pipe outlet has an o-ring that fits over the hole that fits into the underside of the manifold, and the for the Air Bleed Tube, there is no o-ring, but it is either press fit, or glues into place with PVC cement, mating with the center hub on the topside of the manifold. Forget about the valve, this new information has led me to revise my diagnosis 🙂 thanks!
But to inspect a multiport valve, it is easy, just remove the 6 or 8 screws and nuts on the valve cover (don’t lose any!), and then use a small flathead to pry up the valve cover, while lifting up on the valve handle, to remove what’s called the Key Assembly (handle, cover, spring, rotor). Then you will see the black rubber spider gasket, shaped like a web or wagon wheel, either in the valve body facing up, or on some valves it is embedded onto the bottom of the rotor, aka diverter.
Hi, I have a pentair quad 60 DE filter. I recently replaced all 4 of the filter cartridges. When I turn on the pump after letting some air into the system (say after backwashing, or cleaning the strainer basket) a cloud of DE will come out of the return upon initial start up. The DE cloud will disapate, but the DE will settle to the bottom and I’ll be stuck vaccuming again. I don’t notice this behavior upon normal cycling of the pump, and I don’t notice any DE leakage during normal operation. Do you have any idea what might be causing this issue? thank you!
Hi John, that’s a strange one, but it might be a valve problem, and not a filter problem. My theory is that the DE and water run out of the filter briefly if the pump lid comes off or the air bleeder is opened, and the de powder comes into the valve, and maybe enters the pump too. Then when the pump starts again, the multiport valve, which bypasses a little water all the time, but you don’t notice that, bypasses some of the de powder back to the pool. So open up the valve and inspect the gasket and the valve spring, to see if anything looks amiss, or damaged. I’m thinking a bad spider gasket might allow what you describe.
Hi! We have a Hayward Perflex DE filter and super pump. Skimmer isn’t suctioning, high PSI and DE back in the pool. We replaced the gasket on the skimmer part on the pump and also noticed the elbow inside the filter assembly is cracked. What could be the issue?
The cracked elbow could explain the DE back into the pool. You may be able to fix that with ABS glue, or with an epoxy putty like Pool Putty. Have you removed the filter ‘nest assembly’ recently for cleaning? If not that would be the first thing to try, hose it off well and soak in a 5-gal bucket of warm water and 1 cup TSP to remove any oils, then rinse off well, and soak again in a 5-gal water with 2 cups of liquid or dry acid, to remove any scale., Rinse off well again and reassemble into filter tank. Startup and add the required amount of DE powder, remembering that one pound of DE powder is 32 oz of dry measure, not 16 oz as one may think, because it’s so ‘fluffy’.
Hey, I have a brand new (installed sep 19) FNS Plus Fiberglass DE Filter. The drain plug keeps dripping. I’ve tried to tighten it, but it drips none the less. Are there any special ways to tighten it? I’ve used a 7/8 ratchet wrench.
Hi Lance, they have an o-ring on the plug, make sure it is there, and lube can help it seal and protect it. If still leaking, use Teflon tape and wrap the plug threads 3x clockwise with the tape, and screw back in. If you unscrew it just a little, you may be able to get the Teflon tape on there, without removing the plug fully.
Hi. I’m troubleshooting my system right now to try to figure out why DE went into my pool. My question is this: will DE in the pool damage my new plaster? I had the pool replastered five days ago.
Hi, I don’t think so – no, not at all. No worries there at least!
Hi, I have a Pentair FNS Plus – I replaced all the grids and the o-ring on the standpipe and the Pentair push/pull slide valve a week ago. I replaced the manifold last summer and it looks good. Now DE is leaking into the pool. Does the valve have to be installed in a certain way ? I lubricated the valve o-rings per the instructions. Thanks
Kevin, How about the air bleeder screen or ‘sock’ on the manifold? Or is the assembly very tight, with both wing nuts tight and the grids pushed up fully into the manifold? If loose the DE can enter where the plastic grid fits into the manifold. The valve does not need to be installed any particular way, but it’s the same as before? Up for filter and down to backwash, I think for DE filters? Probably not a valve problem. Sometimes a filter air leak can cause the filter to drain water and DE into the pool, check the air bleeder on top of the tank, or the belly band o-ring.
is there a ‘right way’ to position the oring? ie is there a TOP or BOTTOM to it?
No, not a top and bottom, but it can help to reposition the o-ring. And be sure it is clean and lubed (with Teflon based pool lube) If it seems distended, or stretched out, throw it in the freezer for ten minutes, and then it will be smaller.
I have a Hayward D.E. 3600 Micro Clear filter
and I am looking to replace the bolts and nuts of the band clamp.
I was even looking for a new band clamp, but can´t find it anywhere.
Any Help Would be appreciated!
Yep, those are no longer available, the clamp band was deemed unsafe, as Hayward customers suffered several injuries and a fatality, long ago. The only option that I can give, is to suggest a replacement to DE3620 model. You may be able to rethread the bolt and find a new barrel nut at a hardware store, but you didn’t hear it from me!
We have a Hayward Perflex EC50C90 filter. The diaphragm gasket has been leaking for a while. We lubed it and it still leaks. We bought a replacement gasket but can’t figure out how to remove the old one. We can get the top off the filter but have no idea where to go from there.
Marshall, remove the bolts/nuts that hold the two plates (top and bottom) together. Then remove the E-clips and pull the top plate off vertically over the rod. Then you can get at the gasket. While you are in there, pull-out the entire nest assembly and soak the flex tubes in a Filter Cleaner, to remove scale and oils, after you put it all back together, but before closing up the lid.
I have a Hayward Pro-Grid DE filter (model DE4820). The filter is working, but it is leaking around the aluminum clamp that holds the top and bottom together. What part do I need to fix this leak? Is is a Hayward Reinforced Filter Seal?
First, try to reseal it. open bleeder to let tank drain down, remove gasket and clean it well. Clean all the DE off of the tank halves. Lube the oring liberally and reseat the lid halves and place the clamp, but in a different location this time, and tighten it up. Use a mallet or hammer to tap the clamp, a few times, as you tighten it. Tighten the bolt until all the spring coils are touching each other. Start the filter with the air bleeder open. If it leaks again, reposition the tank top and clamp again. If it leaks after that – inspect the o-ring for damage.
Hello. I have a Pantair 4000series filter and it exploded last night and It has a big crack at the bottom bowl. I want to know if this was due to the negligence of my pool cleaner? I don’t know what the pressure was before but I know that the pool filter has not been cleaned for the last seven months. How would this happen?
Sheila, so the tank ruptured and cracked the bottom of the tank? Wow, coulda hurt someone. Prolly lost a lot of pool water. It could be due to not backwashing the filter, or having too much DE powder, if the pressure was consistently higher and near 50 psi, the max working pressure for most pool filters. It could also be a return valve left closed, or some other obstruction on the return side, after the filter, raising pressure inside the tank even more.
H, I have a Jandy DEV48 filter. It’s one year old and we are trying to close the filter clamp. We get the clamp to be 1/4” width and cannot get it to be 1/16 inch as recommended. We’ve tapped it with the rubber mallet while tightening. Any other tips or tricks? Thank you!
Other tips include: repositioning the belly band o-ring, and cleaning and lubing the o-ring with Teflon based pool lube. Dirt, debris or de powder can get in the way. Repositioning the top lid can sometimes help, and/or repositioning the clamp band. The top and bottom halves should touch before the clamp goes on, or nearly touch. a good socket wrench is sometimes necessary on the barrel nut, to prevent stripping and for increased leverage.