Best Chemicals for Winterized Pools

By the time I am done wrestling my Big Green Safety Cover into place, I am ready to forget about my pool until the spring. And, the last thing I want to think about is buying more pool chemicals. Over the years, I’ve learned a few valuable lessons and tips to actually buy less pool chemicals by buying a few key pool chemicals for the winter.

This has actually saves me money in the long run because my pool is in much better shape when it comes time for round two vs my safety cover in the spring. dose of the right stuff in the middle of the winter and at the beginning of spring helps fight algae, staining, and removes organics, dirt and tannins that lurk beneath pool safety covers.

I winterize my pool with a winter closing kit every year. They are a great way to get everything at once at a discount price. For my pool, winter kits are a great way to start the winter but I need a little back up, to avoid the Creature from the Black Lagoon, next year!.


Algaecide 60 Plus

Depending on the size of your pool, and condition of your cover, an extra bottle of Algaecide 60 Plus can go a long way. It’s great for those of us with a lot of spring sun beating down on the cover. I like to add a quart of Poly 60+ to my 20K gallon pool when the weather begins to warm-up noticeably, or about a month before opening.


SeaKlear Free & Klear Clarifier

SeaKlear Free & Klear Clarifier is great because it thrives in cold water conditions which is important to note because not all pool chemicals are effective when the water temperatures get near freezing. It’s a 3-1 product that helps eliminate phosphates (algae food), acts as a clarifier, and helps prevent staining from organic oils and debris. It’s also natural, an enzyme-based product which is good for everyone but also safe to use with other harsher chemicals. The enzymes deteriorate non-living organic debris like leaves and oils that can cause staining as well as tiny particles that lead to cloudy water. Great helper chemical.

Pool Magic Spring & Fall

Pool Magic Spring & Fall is a great way to add enzymes to the pool with a blend of clarifiers and stain fighters, made with Natural Chemistry’s Smart-Zyme technology, designed specifically to work in cold water. 1 bottle or liter of Pool Magic Plus can treat a 25k pool. I recommend using half a few weeks after closing, and the other half a few weeks before opening. I just pour it right through the (mesh) pool cover and let it work its “magic’.

AquaPill – WinterPill

This little guy has received quite a bit of attention this year, with a video released last winter that went semi-viral. The wildly popular Aquapill WinterPill is packs a potent punch from its concoction of natural enzyme, algaecide and stain fighters. 1 WinterPill can treat up to 30k gallons of water. With a small pin puncture (pin actually included) it slowly releases its concentrated solution as it floats freely on the surface of your pool.

Di-Zap Multi-Shock

Di-Zap is a premium pool shock blend that combines Dichlor, Algaecide, and Stabilizer for a 3-in-1 formula that is safe for all surfaces. 1 bag treats 10k gallons. For pools that don’t use a winter cover, or for those that may have suffered a mid-winter cover disaster, Di-Zap makes an excellent treatment for the closed or semi-closed pool. Also can be used monthly during winter, to maintain a constant chlorine level all winter.

Super Stain Away

Super Stain Away can be used on all types of pools but it excels for concrete and plaster pools in the prevention of stains (metal and organic) as well as for pool calcium build up prevention. It can even help fade existing stains. A little goes a long way, 16 ounces is good enough for a 10K pool and you only need to add it once in the winter. If you choose to add it monthly or more only use 2 oz per 10k.

Jack’s Magic The Vinyl Liner Blue Stuff Stain Preventer

Similar to Super Stain away, Jack’s Magic Vinyl Liner Blue Stuff prevents stains, fights scaling, is particular great for water with high traces of metals but it is specially formulated to be gentle on vinyl liners. It also excels in water that has high levels of sanitizer. So, it won’t go to waste if you shock your pool and add some Jack’s Magic to it at the same time. No waiting. Besides being a rock star to protect vinyl, Jack’s Magic is also great for fiberglass pools.

Jumbo Chlorine Floater

Smaller chlorinators can go through all of their contents within a few months, even if the openings are shut tightly. Filling our Jumbo floating chlorinator with 5 lbs of chlorine tablets can make a big impact on how clean your pool is when you open it. I recommend tethering the floater to the edge of your pool (with enough slack to roam), so it won’t get stuck on a step, and for easy access to refill the floater.


Pool Maintenance is a year round job and while we don’t have to work quite as hard in the winter, a little mindful care to the pool water will save money and time. Once the weather warms-up, algae becomes more stubborn, there’s more pollen, there’s more rain, and there’s more excitement to get that pool open for the summer. Make things easier on yourself with these easily applied, potent winter pool chemicals.


Ryan Dornan
InTheSwim Staff Blogger



Chlorine Shelf Life: How Long Can I Store Pool Chemicals?

Dr. Pool of In The SwimWelcome back students of pool – today’s lecture is on chlorine shelf life, and more specifically, do pool chemicals expire, or do they lose efficacy over time?

In an ideal world, the pool season would end just as you use-up the last chlorine tablet, pour-in your last bags of pool shock, and perfectly adjust your water balance with the last scoops from the bucket.

However, one look inside of any pool owner’s chemical closet will tell you that leftover pool chemicals are the norm. So then, do pool chemicals go bad, and will they still work next season?

Shelf Life of Pool Chemicals

Liquid Chlorine

Sodium Hypochlorite, or chlorine bleach is a comparatively unstable form of chlorine, in that it can lose up to 50% potency within the first 6 months, and 90% within one year. If subjected to hot or cold temperatures or direct sunlight, degradation occurs more quickly. For a more stable product, see our Instant Liquid Chlorine in a bottle.

Tablet Chlorine

Trichlor tablets have the longest chlorine shelf life. We have lab tested our individually wrapped tablets for potency over time. At 36 months, InTheSwim tablets still have 98% of their original available chlorine, when stored in constant 50-70° F temps with a tightly closed bucket lid. In the right conditions, trichlor tablets can remain viable for over 5 years.

Granular Chlorine

Chlorine granules sold in bucketsCalcium Hypochlorite, aka pool shock or granular chlorine also has a long shelf life, if kept in an air tight container, in a cool and dry (indoor) location. Pool shock in 1 lb. bags absorb moisture from humid air, and bags can dissolve in 12-24 months (!). For longer term storage, re-pack into zip-loc freezer bags or buy Chlorine Granules, sold in buckets. Properly stored, pool shock has a shelf life of over 5 years.


Cyanuric acid, or chlorine stabilizer will maintain potency indefinitely, even if it absorbs moisture, as long as it is stored in a tightly closed container. Be sure to label cyanuric acid as Conditioner or Stabilizer, so the white powder won’t be confused with another chemical, if the container label fades or becomes unreadable.


When properly stored (cool and dry indoor location), pool algaecides are quite stable and most will maintain potency for at up to 5 years. Temperatures over 75° and direct sunlight will reduce algaecide shelf life, especially lower concentration algaecides (10% and 30% formulations), but freezing temperatures can ruin pool algaecide.


Similar to algaecides, pool clarifiers have a shelf life of up to 5 years, stored tightly closed in consistently cool temperatures, in a dark cabinet or container. Outdoor storage in a garage or shed with high temperatures can reduce effectiveness, and freezing can damage the polyamide structure, rendering clarifiers useless.

Stain & Scale

Most Stain & Scale chemicals, such as our Stain Away product have an indefinite shelf life, with the usual caveat – when closed tightly and stored in a cool, dry location (indoors). As with other liquid pool chemicals sold in bottles, the formulations are very stable, but high and low temperatures should be avoided to maintain product strength.

Alkalinity & Calcium Increaser

Sodium Bicarbonate and Calcium Carbonate are both dry white powder or flake chemicals, and both can remain viable and potent for over 5 years. As with other dry pool chemicals, shelf life can be extended with tightly closed lids to keep out moisture, which can cause clumping and hardening of your water balance chemicals.

pH Increaser

Sodium carbonate or soda ash (pH Increaser) can remain viable for over 5 years, when stored in an air-tight container, to lock out moisture. If stored outdoors, humid conditions can pull moisture into the bucket, clumping and hardening, but also converting sodium carbonate to sodium bicarbonate over time, slightly reducing effect on pH.

pH Decreaser

Sodium Bisulfate and muriatic acid could have a 5 year shelf life, however pH decreasers are acids, and a larger shelf life concern about pH decreasers is the strength of the container. Over time, thin plastic bottles or packaging can break down from contact with acids. So, although pH-Down chemicals last for years, you should probably use them up.

So then class, what have we learned today? 

Most pool chemicals have a shelf life of 3-5 years, when stored properly:

  1. Consistent and cool temperatures, in a dry and dark location.
  2. Tight bucket lids and bottle caps to lock out moisture and contaminants.
  3. Granular Chlorine can dissolve packaging, repack for long-term storage.
  4. Keep all pool chemicals out of reach of children.


Class Dismissed!


Dr. Pool





Happy 35th Birthday to InTheSwim!

In The Swim is celebrating 35 years of providing low cost pool supplies to the do it yourself pool owner – and we couldn’t have done it without YOU!

Back in 1982, our founders, a husband and wife team, were in the solar heating business, helping pool owners heat their cold Chicago-land pools. After being asked for the umpteenth time about where the best place to buy pool supplies was – they decided to expand their product line, to include chemicals, equipment and accessories. is now one of the largest online pool supply retailers, but 35 years ago, the world wide web did not exist – and orders were placed over the phone or by mail, through our pool supply catalog, which is still mailed to millions of homes each year.

Since our first 12-page catalog, we’ve expanded our residential catalog to over 50 pages, and also produced 60+ page catalogs for Commercial pool managers and Wholesale buyers.

As mail-order sales took off (in the days before the internet), our founders dabbled in other fun catalogs over the years, including a pool parts catalog, a hot tub catalog, and even a ski and snowboard catalog!

Intheswim website, 1999In 1997, things all changed – for the better, when came online. For an old catalog company from the 80’s, a website was just an electronic catalog, accessible to anyone with a (dial-up) internet connection!

At the time that the commercial internet was born, postage rates were going up, and the ability to put your catalog online, and edit products on-the-fly, were big advantages over printing millions of catalogs each year. It was thought to be the death of mail-order catalogs.

Only it wasn’t – and anyone with a mailbox can tell you that – over the last 30 years, catalog retailing has not only Not Died, but has become more ubiquitous than ever. And although it’s not so common anymore, we still get checks in the mail with the mail-order form attached. For most folks however, our catalog that comes in the mail is a useful reminder that it’s time to buy pool supplies, even if they order by phone or on our website.


Fast forward to 2017, hundreds of staffers fill our 100,000 sq ft warehouse, filled with thousands of pool products. Plus, we have 9 other warehouses around the country for faster shipments. And, we also stock tens of thousands of replacement pool equipment parts.

With free shipping and one day delivery on most items, you can be sure that your pool supplies will arrive when you need it. On time – Every time, is our motto.

In The Swim’s 24 hour ordering service allows you to place your order online or by phone at any time that’s convenient for you. And a 30-day money back guarantee that proves our commitment to meet and even surpass all of your expectations!

And the best part about working here? The laughter and support from people whom I’ve spent the last ten years with, and of course YOU, our valuable customers – who have rewarded our hard work with a steadfast loyalty that is simply amazing.

We couldn’t have done it without YOU.

35 years. Wow. Thank YOU, America!


Sabrina Potirala
InTheSwim Staff Blogger


Dealing With Excessive Leaves In Your Pool

I Love to Skim my Pool. Part of me appreciates the subtle Zen-like qualities of walking around the perimeter of my pool collecting every visible scrap of debris visible to the naked eye, clearing the water and my mind. It’s me time.

If I’m in my pool, the leaf net is always close at hand. However, I have a tree that is actually in my front yard that manages to shed various pods, seedlings, and an array of leaves throughout the year that inevitably land in my pool. It can get excessive in the fall.

This is the time of year that most of us are dealing with heavy amounts of leaves in our pool area regardless if your pool is open or closed. I’ve collected a handful of my favorite anti-leaf tools to assist you in your own fight for a debris-free pool. Let’s jump in!

Leaf Bone – Leaf Net Skimmer Clip

Leaf Bone, skimmer net clipThe Leaf Bone Leaf Net Skimmer Clip is a $12 tool that falls into the It’s-So-Simple-It’s-Genius category of new additions to the pool maintenance world. This nifty Clip fits any 1.90” inground pool ladder handrail, installs in seconds, and can spare your pump the extra energy from decrease water flow from a leaf-clogged skimmer as well as save time from manually patrolling the pool with your leaf rake in hand.

Pool Cover Leaf Catchers

Pool Cover Leaf Catchers

If your pool has large trees nearby, leaves and sticks can create problems for pool covers. A simple, lightweight solution to leaves and debris is a leaf catcher. Leaf Catchers act as a protective net that rests over the top of your winter cover to collect all fall leaves. Super easy to remove, with a winter’s worth of leaves in tow. Inexpensive and available in a variety of sizes for both inground and above ground pools. Pool Leaf Covers protect your cover, and save you a lot of time and effort.

Leaf Gulper Garden Hose Vacuum

pool floor vacuum garden hose styleThe Leaf Gulper pool bottom cleaner connects to your telescoping pole like a vacuum head, but  instead of a vacuum hose it uses a garden hose. The water from your garden hose blows the leaves up into the net as you roll over the. The bottom has a soft thistle brush that is safe for concrete, fiberglass or vinyl liners. The Pool Blaster is the exact same premise only it functions via a battery powered fan that sucks up the leaves into the bag.

In-Line Leaf Strainers

Hayward Leaf CanistersHayward Leaf Canisters attach to your manual pool vacuum or suction pool cleaner with a short hose that connects to the skimmer. The basket or bag collects the leaves to prevent them from going through your pool plumbing (potentially clogging it). Stops leaves from collecting in your pump basket, so you don’t have to stop vacuuming to empty the pump or skimmer basket. Plus, large-capacity leaf strainer traps leaves and debris, avoiding a loss of suction from blocked baskets.

Skim It Pool Cleaner

Skim-It for pool skimmersThe Skim-It Pool Cleaner is another one of those brilliantly simple accessories that works for both inground and above ground pools at a cheap price that takes ZERO effort to install. The part that attaches to the inside of the pool skimmer is simple a tension spring—like a mini tension curtain rod. The Skim It extends the reach of your skimmer, trapping the debris so that the skimmer can coral it into the basket. I use a Skim-It on both of my pool skimmers.

24″ Soft Mesh Leaf Rake

Our 24” Pool Leaf Rake skims and scoops leaves, sticks, and larger debris with ease! This heavy-duty pool cleaning tool features a solid aluminum frame and handle with a plastic rim that’s beveled for pool floor cleaning. This leaf rake also features a rugged, lightweight, soft mesh fabric that makes it easier to pull through water so cleaning is faster, especially when full of debris. The special fabric  also makes it super easy to empty!

Pro Dual Cam Telepole

The Pro Dual Cam Pole features both an internal and external cam that makes extending, locking, and closing quick and easy. With two locks in place, inner poles will not slip. The Pro Pole is 30% thicker than standard poles, extends from 8-16’, and has a soft rubber grip and handle that’s super comfortable to hold. Best of all, the Pro has an EZ release system that makes interchanging tools like your leaf net, brush, or vacuum, easier than other poles and protects the pole end from damage.

Natural Chemistry Phosfree

Another hidden nuisance leaves can contribute to is algae. Leaves contain phosphates which are the food that spawns algae growth. Excessive leaves can ultimately result in excessive algae. Natural Chemistry’s PHOSfree is not an algaecide but more of a natural algae prevention solution. Just add the recommended dosage of PHOSfree to your pool with the filter running. Especially recommended for mesh covered pools, or any pool with algae problems from heavy organic loads.


I highly recommend all of these suggestions for any above ground or inground pool owner. I’ve found that I need to pursue other Zen outlets because I don’t spend as much time strolling around my pool ridding the water of leaves and debris. All of these simple devices and natural chemicals will save you time, effort and perhaps, most importantly… money!


Ryan Dornan
InTheSwim Staff Blogger


5 Above Ground Pool Winter Cover Tips

Winter Pool Covers take a beating every winter as they protect above ground pools from the nastiest of elements: rain, ice, snow and especially wind can take a toll on your pool if not winterized and covered correctly.

Aboveground winter covers in particular can cause lots of problems if not properly installed. Haphazardly placed covers are a sure-fire way to shorten the lifespan of the cover and possibly your pool.

To protect your cover and your pool… 5 aboveground pool winter cover tips.

ABG Pool Cover Tip #1: Pool Air Pillows

Above ground pool owners will be relieved to know that most of these tips involve very simple and affordable solutions, perfectly exemplified by Air Pillows. Winter cover air pillows are used to keep a solid ice sheet from forming on the surface of your pool water.

Air Pillows are placed in the center of the pool, with the pool cover pulled tight over the pillow to press it into the water. Pool Pillow Pal is a $10 accessory to hold the air pillow in the center of the pool. Tip: Inflate your air pillows in seconds with a Shop Vac.

Winter Pool Cover Tip #2: Beware the Wind

Wind is possibly an above ground pool cover’s worst enemy. Above ground covers can be trashed if winds gets under the edges and begins to whip and flap the cover.

Secure the winter cover cable tightly with the wench (included with all above ground winter pool covers). However, that’s not enough to stop strong wind. Some folks weigh down the cable, with milk jugs or use our Wall Bags, which is fine for moderate  winds.

The best options to keep out heavy winds are either Cover Seal (shown) or Cover Clips, both made for this purpose, with the added benefit of keeping your cover taut and smooth all winter.

Winter Pool Cover Tip #3: Mind the Water Level

It’s important to keep an eye on your pool’s water level. If it drops more than an inch, it can stress the cover and the pool. If the pool loses 6-12″ of water, with rain water pooling on top of the cover, it will damage the cover and possibly the pool. Fix leaks before closing, or add water under the cover if needed.

Also important to mind the water level on-top of of your winter cover. A small bit (1/4″-1/2″) of rain water is OK, but more than that could stress the cover, and 6-12″ of water will push pool water over the edges, lowering pool water (see above).

Pump regularly with a pool cover pump like our manual or automatic 350 GPH pump or the non-electric Cover Saver siphon pump (shown).

Pump the water a good distance, to avoid over-saturating ground near the pool,and be careful not to pump out pool water through holes in your winter cover! If the cover has small holes, place the pump far from holes, or use upside-down Frisbee as a pump base.

Winter Pool Cover Tip #4: Leaf it Alone

Leaves on the pool cover can get real messy, real fast. Trying to remove leaves and sticks with a skimmer net or pool brush is not very effective. Instead use a Pool Leaf Rake to scoop it off – much more effective, but not easy, definitely not fun, and sharp sticks could damage a pool cover.

If your pool has large trees within 50 ft. – take a look at our Leaf Nets for above ground pools. Place this over your pool cover when closing, and remove after all leaves have fallen. Two people can remove every leaf in seconds, and easily carry it away. That’s Fun! Super durable carbonized mesh can also be used spring and fall, to keep an open pool clean.

Winter Pool Cover Tip #5: Cover Checks

If you are like me, once you winterize, and you know you’ve done it right, you probably try not to think about your pool until the spring. I’ve learned that this is a huge mistake. Tending to your above ground pool is essentially a year round responsibility.

Final Tip: you can’t just set it and forget it. You will need to visit your pool cover regularly, not just for dewatering and dredging activities, but to tighten-up the cover to pull out slack, correct wind gaps, readjust the air pillow(s). It only take a few moments a couple of times a month to run a quick check. The money you save via damage control is worth the effort.

Of course, using those aforementioned products – Leaf Catcher, Pillow Pal, automatic cover pump and Cover Clips or Cover Seal, goes a long way towards an (almost) maintenance-free aboveground pool cover.

Now You’re Ready to Close the Pool!

These above ground pool covering tips are affordable, simple, and do not require a whole lot of your time – which makes them easy to neglect. As a pool owner, the cheapest, quickest path isn’t always (almost never) the best path.

An above ground pool winter cover is an investment that protects a much larger investment: your pool! Spend a few extra bucks for a good cover, and spend time to do things right, along with the right winter cover accessories, and you can avoid mid-winter cover disasters!


Ryan Dornan
InTheSwim Staff Blogger


Hiding Pool Equipment with Landscaping

Swimming pools are beautiful: sparkling blue water, and inviting pool decks can be just as aesthetically pleasing to look at as they are fun to swim in. Pool equipment, not so much.

PVC plumbing, pumps, filters and heaters are obvious necessities for all of us pool owners but any pool owner can attest that we would rather see the results of the equipment without the constant reminder of their presence.

I’ve tackled the topic of Pool Equipment Enclosures in a previous blog with a nuts and bolts approach to building walls around pool pump and filters. Today we approach hiding pool equipment with a greener approach: with Plants.

Landscaping Ideas to Hide Pool Equipment

There are a number of ways to use the landscape or enhance the landscape to hide pool equipment and redirect sound from noisy pool pumps. A combination of grading and planting can be used to block the view and the sound.

Hills & Valleys

One of the oldest landscaping tricks is to sculpt the land to make it more pleasing to the eye. Whether an entire dump truck full of fill dirt, or a few yards of topsoil, you can make a nice cerrito, or small hill to hide the pool equipment, and deflect pool pump noise.

Adding a berm or mound in front of the equipment won’t work for everyone, you need to have extra space, a big wheelbarrow and a strong back.

Shown here is a delivery of 5 yards of topsoil, but just 1 yard of topsoil can be used create a 3′ x 8′ berm about 12″ high, that can be planted with grasses or bushes.

Ornamental Grasses

Tall native grasses like Karl Reed Forester can be an affordable solution to hiding your pool equipment area. Many grow tall enough to thoroughly screen the largest of pool heaters, and they are relatively low maintenance.

Installing a low and tight fence, 2-3 ft high, between the grasses and the filter system, serves to separate the two, and also will reflect pump noise away from the house. Some of the best grasses for screening purposes are:

Maiden Grass – Miscanthus gracillimus

The most common of all the tall grasses. Maiden Grass has a narrow green leaf blade with a white stripe in the middle. Maiden can grow up to 5’ or 6’ tall and up to 5’ wide and each year that it grows back it grows a little bit bigger. It plumes in late September in a nice shade of maroon and then fades to silver.

Morning Light Grass Miscanthus sinensis

Maiden grasses little sister is Morning Light. If your space isn’t big enough for a robust grass like Maiden Grass, Morning Light is very similar only much smaller! They take a few years to come in, faster with water and fertilizer. Prune them back in the early spring to remove dead wood, and they’ll push out new shoots in place.

Plume Raven Grass – Saccharum ravennae

Plume Raven is similar to Pompas grass or Fountain grass, but is more hardy for colder winter climates. Plume Raven has a wider blade than Maiden and is a lighter shade of green but it grows much taller, up to 8’ tall in just a few years. Puts forth later summer growth, and can actually jump-up another 4’ when displaying its purple plumes in September.

Zebra Grass – Miscanthus zebrinus

The blades of Zebra Grass are wider than Maiden and noticeably a brighter shade of green. It can grow 5’ to 8’ tall and up to 6’  wide. It has a light pink plume appears in late August. It’s a bit floppier than the previously mentioned grasses but can add a unique accent. An alternative to Zebra Grass is Japanese Silver Grass. It’s much lighter in color but similar in size.

Other notable ornamental grasses are Switch Grass, Giant Miscathus, Ravenna Grass, and Giant Feather Grass. Most ornamental grasses are hardy for zones 5-9 (which is most of the US), and can be cut back and mulched-over for winter in northern zones 3-4.

Bushy Bushes

The big brother of grass, bushes are a step up from tall grasses and can serve as a much denser natural screen. Evergreen bushes work year round and many bushes offer the versatility of thriving in large planters giving you opportunities to flash your style. Ask at your local nursery, some bushes can get messy and produce debris that lands in your pool, and others can grow too big, too fast.

So there you have it America! If you want to soften the backyard, add bushy bushes and fluffy grasses to hide your pool equipment and reduce pump noise.

Just be sure to give lots of room for the plants to grow, without blocking sunlight and air flow to the equipment. Or if needed, grasses and bushes can be easily pruned, any time of year.



Sheryl Sollis
InTheSwim Staff Blogger



What Happens If I Don’t Close My Pool?

If you have closed your pool already, then I say congratulations and sorry at the same time – congrats for getting it done already and sorry your summer is over. This blog post however, is not about crying for the season passed, but for folks out there with a pool, thinking they might leave their pool open for the winter.

You may want to close your pool before the weatherman gives frost warnings in your area – we’re about to show you what happens if you don’t close your pool and have even just occasional winter temperatures below the freezing mark.

Fair warning, it’s not pretty. Some of the images might make you break out in a cold sweat and give your wallet and bank account a case of the shivers. So . . .

Q: What happens if I don’t close my pool?
A: It falls apart.

There you have it in plain terms. Don’t believe me? I’m not trying to scare you, but there are a whole host of potential damage that could occur to pools – if the pumps aren’t running when temperatures dip below freezing. Let’s move on to specifics.


One of the most important things you do when closing a pool is ensuring the pool water level is below the your pool filter system intake along with getting all the water out of your pool equipment and pipes.

If there is any water left in the pipes of your pool plumbing, the water will freeze, and Physics 101 class tells us water expands when it freezes, up to 10%, and that’s enough to crack pipes, pumps, filters, heaters, skimmers, and other things – that are full of water.

If pool pipes or equipment is only half full of water for example, there may be enough space for the ice to expand into, maybe. But until you’ve done some winterization, your pool equipment and pipes are likely very full of water.

If you have an above ground pool with the pool filter system and plumbing above ground (like nearly all above ground pools), pipes and pumps can freeze up in less than an hour of minus 32 degrees. The same is true for inground pool equipment that is not running when temperatures are below freezing. As long as water is moving through all pipes and all equipment, nothing will freeze.

Water in underground pipes won’t freeze right away, it takes several days of below freezing temps before the soil freezes. I’ve been told that the frost goes into the ground about an inch per day, when temps remain below 32°, day and night, for long periods of time. Daytime warm-ups can thaw soils just as rapidly, however. As such, it can take a week or two of consecutive days below freezing, before (well-buried) pipes are in danger of freezing.


a pool pump leaks in many places after water inside it freezesThis is what a pool pump looks like when you turn it on after it was damaged by ice. At least PVC pipes and connectors are rather inexpensive and easy to replace. Depending on what type of pool pump you have, buying a new pump housing can cost several hundred dollars more than PVC pipe.

To winterize a pool pump (even if just for one night), remove the 2 plugs from the pump.


And don’t think your pool heater is stronger. Cast Iron and Polymer heater headers are usually the first thing to snap in a sudden freeze. And it’s fortunate that they do, which drains the heater and avoids much great damage.

To winterize a pool heater (even for just one night), remove the front and rear header drain plugs, and disconnect the pressure switch inside the heater. Blowing air through the heater is recommended, to remove all of the water.


Your pool filter tank can withstand enormous pressure, up to 50 psi in most cases, but that’s still no match for the power of expanding ice. In some cases, the tank itself will crack, or the clamp ring on cartridge or DE filters will crack in half, or the top mounted multiport valve flange will separate from the tank, or just start leaking, as shown here.

To winterize a pool filter (even just for one night), open the air bleeder and remove the filter drain cap or drain plug. If you have a multiport valve, turn the handle to a spot in between any two positions, and if you have a push-pull slide valve, place it mid-way between up and down positions.


For inground pools, that nasty spring opening surprise could be even worse because your pool pump and filter will start going, and then you’ll notice the equipment isn’t working right and wonder why. It’s because you can’t see the broken pipes that are leaking three feet under your concrete pool deck.

Replacing busted up pool plumbing is one thing, having to cut through your concrete pool deck and dig down several feet to fix the plumbing is quite another thing. Let’s not forget, if your pipes are freezing, there’s probably a real good chance your pool equipment is too.


If you have an above ground pool, there’s something unique that can happen if you don’t use an air pillow or don’t winterize the skimmer properly, they crumple like tin cans.

An above ground pool is designed to contain the water inside of it, but as an ice sheet thickens across the pool, it puts outward stress on the walls. When the ice sheet is also frozen inside the skimmer – any heaving, tilting or slipping of the ice sheet can wreak havoc on even the strongest aboveground pools. In this case, a water leak left no support for a 6″ thick ice sheet.

If you still want to keep the pool open, In The Swim carries the lifesaving Intermatic freeze sensor, compatible with with the PE153 Digital Timeclock. This allows you to pre-set a temperature for the pump to turn on, automatically (so you don’t have to).

Or, if you go ahead an winterize, don’t forget Air Pillows and Skimmer Plugs to protect your pool, and for inground pools, new winter pool plugs and pool cover supplies are in order. And every well-winterized pool can find a cheap insurance policy in pool anti-freeze.

If it’s too late to winterize, and if your pool equipment is already frozen, remove the drain plugs, throw heavy blankets or tarps over the equipment, and set-up a small space heater with plenty of ventilation, you don’t want it to catch on fire next!

For those of you on the fence, you should seriously consider going the pool closing route. Now is the time to do it, and if budget is an issue, In The Swim offers some nice winter covers along with pool winter kits at good prices, right now.


Larry Andersen
InTheSwim Staff Blogger


Favorite Swimming Pools are Clean, Are You?

Swimming Pools are Clean, Are You?
As a blogger for all things pools, I have my eyes and ears open for interesting swimming pool news. On a daily basis, I comb the internet for interesting tidbits, stories of exotic animals in pools, cannonball contests, and useful maintenance tips. As such, I have to wade through sometimes hyped-up warnings regarding the dangers of germs in pools, causing RWI’s.


If you are unfamiliar with Recreational Water Illnesses or RWI’s, the most common examples are diarrheal illnesses (spread by swallowing contaminated water), rashes, swimmer’s ear, eye infections, respiratory infections, or infected wounds. The Kingpin Germ Villain today is ‘Crypto’, or Cryptosporidium, and it even sounds menacing.

If you didn’t know any better, a quick Google search would lead you to believe that pools are summer’s biggest menace. In fact, I just read a 4-page article that served up 3.5 pages of all the horrible germs and diseases that await us all if we go in the water. The article ended abruptly with a short list of bulleted tips:

• Don’t use your pool as a toilet
• Don’t let other people use a pool as a toilet
• Don’t use your pool as a bathtub, be cleanNick Cage - "You Don't Say!" meme
• Don’t swim in the pool if you have diarrhea
• Don’t drink your pool water even if it is not being used as a toilet

This is pretty basic stuff. Let’s put things in perspective:
There is another place that has a similar set of rules: the kitchen. According to the CDC, 1 in 6 Americans, or roughly 48 million people, get sick from food poisoning caused by similar germs and bacteria. That’s a lot of people.

There are an estimated 10,000 cases of RWI’s annually, and that number in recent years has admittedly been increasing. Thankfully, the internet isn’t awash in reports and warnings from Mommy Bloggers about the dangers of going to restaurants. Or maybe there, are…do poor reviews count?

Q: Who Do We Blame? A: The Children!
Let’s face it, children are gross little disease-spreading creatures that ruin all the adults’ fun. But there is hope for them yet. It’s important to take smaller children on regular bathroom breaks while swimming and for even smaller children it’s necessary to change their diapers in a proper changing area. You wouldn’t change a diaper on the kitchen counter, so don’t do it by the pool.

Above all, kids and adults should shower after a #2 visit to the bathroom.The pool isn’t a toilet and isn’t a bathtub either. We all joke about peeing in the pool and this lighthearted humor could mask the the importance of personal hygiene especially in the water. Educate first, and then tell the peeing in the pool jokes.

Does Chlorine Effectively Kill All the Germs in a Pool?
The short answer is yes, but some germs are tougher than others. Crypto and Pseudomonas for example, can survive in a properly chlorinated pool. That is why shocking the pool regularly is important, that’s why we do it – to kill bacteria that escape our normal disinfection.

If you are a reader of the In The Swim Blog you hear us repeatedly stress the importance of testing your water as frequently as possible. However, sanitary pool water requires much more – a clean pool, with proper water balance, daily circulation and filtration, a daily sanitizer and regular oxidation (pool shock).

What are the proper pH, Alkalinity and Chlorine Levels for a Pool?

Chlorine Vs. Bacteria cartoonUse a good test kit or test strip that can test all of the important parameters. I like the Taylor K-2005.

  • pH: 7.2-7.8
  • Total Alkalinity: 80-120 ppm
  • Calcium Hardness: 200-400 ppm
  • Chlorine Levels: 1.5-3 ppm
  • Chlorine Stabilizer: 20-50 ppm

When and How Often Should I Shock My Pool?
It’s best to shock your pool in the evening because the sun’s UV light destroys the strength of chlorine. Keep your filter running overnight if possible. Be sure your pH level is correct, or a bit on the low side (7.2), so that the shock oxidizer works most effectively.

  • After a pool party or heavy use
  • At pool start up of for algae treatment
  • After extended periods of heat
  • After heavy rains or leaf litter
  • If there is a strong odor of chlorine
  • If the water appears cloudy or dirty
  • If a raccoon gets into your pool (seriously)*

We already covered that people carry germs but extended periods of hot weather can consume sanitizer, and heavy rains or flooding can flush contaminants into your pool. If you smell a strong odor of chlorine in the pool, this usually means that there is a build-up of chloramines in the water. This can be tested and confirmed with a DPD test kit.

*While most little critters found in the pool are typically harmless raccoons are not. The CDC warns that, “Raccoon feces can sometimes contain the eggs of a worm called Baylisascaris procyonis, which can infect humans, particularly children, and cause neurological illnesses.“

How much Pool Shock to Use?
I consulted with Dr. Pool on this one, and his first response was “it depends”. That is, it depends on what type of issue you are trying to solve.

  • Cloudy Water – 10 ppm
  • Chloramine Removal – 10 ppm
  • Algae Treatment – 10-30 ppm “depends on severity
  • Bacteria Removal – 10-30 ppm “depends on strain“*

*He means “strain” of bacteria. For those “pathogenic bacteria“, ones that make us sick, Dr. Pool says to “shock to 30 ppm“. Use 1.2 lbs of of Pool Shock, or 1.0 lbs of Super Shock, to raise chlorine levels to 10 ppm, per 10,000 gallons of pool water. Or more simply, to reach 30 ppm, use 3-4 lbs of pool shock, per 10,000 gallons “with a suitably low pH“.

In The Swim’s colorful infographic on How Often and When to Shock a Pool

Hungry, Hungry Enzymes: How Do Enzymes Work in Pools?
An unsung hero of the pool sanitizer world are enzymes. Pool Enzymes help make chlorine stronger by essentially eating-up non-living organic materials which turns the byproduct into water (it’s cool if enzymes pee in the pool) which clears the way for chlorine to come through and kick out the troublemakers.

In The Swim also made this equally colorful Pool Enzyme Infographic.

Are Saltwater Pools Better Sanitized Than Chlorine Pools?
It’s a trick question. A Saltwater pool is still disinfected with chlorine. The salt doesn’t disinfect, the salt chlorine generated from a salt cell uses electrolysis with the salt to produce hypochlorous acid (HClO) and sodium hypochlorite (NaClO) which is a fancy way of saying “chlorine”. So no, salt systems are not more effective than chlorine tablets or liquid chlorine.

Don’t Believe the Hype:
If a pool is properly balanced, if your swimmers are clean, and you don’t make a habit of drinking pool water you really have nothing to worry about. It is important to educate yourself and children about the potential to get sick from dirty pool habits, and protect your guests, family and self from potential disease-causing bacteria and germs by sanitizing your pool the right way – Constant and Consistent, with regular super-chlorination or shock treatments.

One more great graphic from the CDC about Healthy Pool Water


Ryan Dornan
InTheSwim Staff Blogger



FilterBalls – Do They Really Work?

Like many of you, I am preparing to close my pool for the winter. This summer went by fast (fastest on record they tell me), and pool maintenance was the easiest it’s ever been for me this past season. Credit some of it to seasoned experience (my 5th year as a pool owner), some credit to the cool weather, but much of the credit has to be given to FilterBalls.

As you may recall from my FilterBalls: a Breakthrough In Pool Filtration Media? blog post earlier this summer, I switched out 250 lbs of greasy, old sand from my Hayward Sand Filter with FilterBalls Filter Media. It was taking a chance because FilterBalls are a radical departure from the familiar, and the pool was just opened, and oh, yeah – the Chicago Bulls were going to film a commercial in my backyard in a matter of days.

It was a risk, but an opportunity I am glad I seized upon. In hindsight, FilterBalls are so much easier to handle than big bags of sand, and if I didn’t like the results they certainly were going to be a million times easier to remove from my pool filter than the slimy old sand I scooped out for over an hour. It would have been a breeze to replace them if they didn’t work as well as the FilterBalls website said they would.

But they did work – FilterBalls work great!

I honestly cannot speak to micron size, or if FilterBalls can trap smaller particulates than regular filter sand. I can say however, that my water never looked better, and without the occasional hazy water that would result if I didn’t do a timely backwash of the sand.

What I can speak of – is catching myself in old habits, compulsively monitoring the filter pressure gauge in anticipation of the next backwash. That was kind of tricky, as my pressure never really went up this summer. I backwashed last month, because it was driving me crazy not to do it at least once. My compulsion got the better of me. 🙂

Another benefit of the lower filter tank pressure was that my return jets were consistently strong all summer. After installing FilterBalls, the pressure gauge dropped 5 psi, and the pool returns flowed stronger than ever and did a great job circulating the water. And my 1.5 horsepower Hayward SuperPump, as reliable and maintenance free as it is, was always a bit noisy – but after FilterBalls were added, the pump was noticeably quieter.

Skim Doctor 2.0I want to tell you about another innovative product that had a hand in my hands-free pool maintenance summer – the Skim Doctor 2.0. I have a weak skimmer in the shallow end of my pool much weaker than the deep end skimmer (closer to the pump), and gave the Skim Doctor a whirl. It’s such a simple little device that it’s practically mad genius. My shallow skimmer now functions as good or better than the deep skimmer.

I was so impressed with the Skim Doctor that I ran inside the house to grab my napping wife and insisted she share in my joy. It wasn’t that she wasn’t impressed, but more like she was furious with me for ruining a rare weekend nap – to look at her least favorite part of the pool. Days later, she would concede that the Skim Doctor was “pretty cool”.

Back to FilterBalls – I mentioned that we used 3 bags of FilterBalls Blu. Actually, we saved a few Balls for other experiments, such as tossing a handful of FilterBalls in the bottom of my Leaf Rake. They are not heavy at the bottom of the net while wet, and they nab what would otherwise pass through the skim net. We get these thin layers of gnats spawning on the water surface in late summer – gross and hard to skim. Not anymore.

I didn’t stop there, though. When the pool turned hazy, because I was being too skimpy with the pump run time (Hi, Davy), I dropped a handful in the bottom of the skimmer baskets to see if they would help clear the water. FilterBalls to the rescue – no need for clarifiers, just 5 or 6 FilterBalls in the skimmer, and by morning, the pool was clear! Amazing.

As for FilterBalls reducing the amount of daily filtering and saving me hundreds of dollars every season – well, it did allow me to run the pump less, not 50% less, but at least 20% less, and every penny counts, right? To be fair, I was already running my pump less than most people anyway.

This weekend, when I pop out the Skim Doctor, blow out the lines, and fill them up with anti-freeze I won’t have to wonder how long it’s going to take for all the water to drain out from the Sand Filter. No worries about damp, freezing sand expanding inside the filter tank and potentially cracking it. The water is going to drain right out, probably in less than 1 minute.

So there it is as promised, my review of FilterBalls, a real-world test of the filter sand alternative, spun polyester balls that are used to replace pool filter sand.

Just 1 lb. of FilterBalls Blu-10 replaces 100 lbs. of filter sand, and 50 lbs of Zeolite or FilterGlass.

FilterBalls really do work! 🙂


Ryan Dornan
InTheSwim Staff Blogger


Favorite 10 Steps to Winterize Above Ground Swimming Pools

pool-closed for winterThis post originally from 2012, is New and Improved and bumped to the top! 

Summer is over and with the end of summer comes the end of swimming; now is the time to prepare your swimming pool for winter.

Here’s my all-new 10 Steps to an above ground pool closing – prevent damage from snow and frozen water, and make pool opening next spring a breeze!

1. Balanced Water Chemistry

Taylor Troubleshooter test kitThe first step before closing the pool is to balance the water chemistry about a week before you are ready to close. Test your pool water and ensure that the chemical levels are within range:

pH: 7.2 – 7.6
Alkalinity: 80 – 120 ppm
Calcium Hardness: 180 – 220 ppm

2. Shock the Pool

pool shock, 1 lb.After balancing the water chemistry, and several days in advance of closing the pool, add a diluted granular chlorine, or non-chlorine pool shock to your pool water to remove any contaminants that could cause stains or algae during winter. The usual treatment is one bag (or pound) per 10,000 gals of pool water, for clear water. If your pool water is hazy or green, add double or triple the normal dosage. Use a brush afterwards, and brush the floor and walls until your arms wear out.

3. Clean the Pool

On the day of the pool closing be ready to clean your pool with your pool vacuum, brush and skimmer net. Clean it well before lowering the water, and skim again before covering the pool, to remove any wind blown debris.

It’s important to close the pool in a spotless condition. Any debris left in the pool will use up your winterizing pool chemicals, affect water balance, and create ugly stains.

4. Remove Accessory Items

hayward skimmer basket and return eyeballsRemove your skimmer basket, return fittings, solar blankets, pool alarms, ladders or steps, and pool cleaners. Dry and stow them safely for the winter months – indoors or protected from the elements.

Solar blankets can be left on the solar reel, and covered with our durable winter solar cover. They can also be dried, folded and stored in a location inaccessible to mice (probably not the shed).

5. Lower Water Level

Skimmer PlugNow, you can save the skimmer and save water at the same time with the aboveground pool Skimmer Plug. Just snap on the plastic skimmer cover and you can keep the water at normal levels. Drain the skimmer pipe, or disconnect the hose connecting to the pump.

If you don’t use a skimmer plug that fits into the opening to block water, you need to lower the water level below the mouth of your skimmer to prevent damage from frozen water. Lower the water level to about 3” below the skimmer opening. Removing too much water could stress your pool cover, liner or pool walls.

You can use your pool cover pump, or let the water run out of the return line hose by disconnecting it from the filter. If you have a low water suction line, in addition to the skimmer, close or plug the skimmer, and use the LWS line to lower the water below the skimmer, by setting the filter valve on waste or disconnecting the plumbing (next).

6. Drain & Plug the Pipes

For the return line, back to the pool: If you have filter hoses, use a #9 winter pool plug, or the threaded 1.5″ plug with o-ring on the return line – on the inside of the pool, and then disconnect the hose, draining it dry. If you have hard PVC pipes that cannot be removed, use a large wet/dry vac to blow (or suck) the water from the pipes, and add pool antifreeze for extra protection.

For the skimmer, remove and drain the hose connected to the pump. If you have hard PVC pipes, drain, suck or blow water out. Use a winter skimmer Plug to keep water out of the pipe during winter. PVC pool pipe cracks easily when the temperature falls below 32 degrees, so be sure that you get all of the water out, or add antifreeze if you’re not sure.

generic skimmer Gizmo, Skimmer GuardThe Skimmer Guard Gizmo is a combination skimmer plug and skimmer protector. It plugs the pipe to keep water out, but also absorbs ice expansion inside the skimmer. Skimmers can fill up during the winter, expand and easily crack a skimmer housing. The Skimmer Guard Gizmo absorbs the expansion, protecting the sidewalls of your skimmer. Includes a #9 rubber expansion plug to seal up the return line.

7. Drain the Equipment

350 gph pool cover pumpThe next step is to drain all the pumping, filtering, heating and chlorinating equipment and blow out all water from plumbing lines, otherwise the water will freeze and crack the equipment. After draining, pool pipes should be sealed at the pool with plugs, to keep water out of the pipes and equipment during winter.

Pumps have 1 or 2 drain plugs.
Filters have 1 cap or plug near the bottom.
Gas Heaters have drain plugs on each side.
Solar pool heaters have a union or a drain cap, or blow air thru the solar panels.
Heat Pumps loosen union nuts, slide back and tip the unit very slightly to drain.
Chlorinators or Purifiers have 1 drain plug.

pool heater and heat pump covers for winterBe sure to shut off the power and gas supply to gas-fired pool heaters. You can protect pool heaters and heat pumps with a Pool Heater Cover to prevent damage caused by snow, dirt, debris and animals. Moth Balls or mint sachets are also effective at keeping nesting mice out of pool heaters.

For DE pool filters and filter cartridges, a final cleaning and inspection is needed while closing the pool. Remove your filter grids or filter cartridge and hose very thoroughly.

Filter CleanerSoak in our Filter Cleaner to have grids or cartridges at their cleanest before replacing into the filter for dry winter storage. Sand filters also benefit from an end of year cleaning to remove oils and mineral scale, before it ‘sits and sets’ all winter long.

Finally at the equipment pad, be sure to shut off all power to the pump, lights, heater and other equipment. If you can easily remove the entire equipment pack for indoor storage, that would be best.

8. Lubricate O-rings

Magic LubeNow is also a good time to lubricate the soft rubber o-rings or threaded metal parts of your equipment. Use a Teflon based pool lube for rubber o-rings on your pump lid o-ring, filter tank o-rings, union o-rings, drain plug o-rings, or any other rubber o-ring on your pool equipment.

9. Add Winter Closing Chemicals

In addition to maintaining good water balance during the winter, adding winter algaecides and chemical floaters ensure that your pool water remains clean and clear during winter. Not having sufficient winter pool chemicals can lead to a long and costly spring clean-up.

A pool winterizing kit makes the process more convenient – just buy the winter kit that matches your pool size. In The Swim winter kits include algaecide, non-chlorine shock, stain & scale preventative, slow release floater and oil absorbing sponge. The Ultimate Winter Kit shown here, is what I use on my own pool, it has a few extra goodies.

10. Cover your Pool

intheswim winter pool coversLast but not the least; cover your pool with a tight fitting pool cover to ensure that debris and leaves cannot get into your pool. Winter Pool Covers for aboveground pools come in a variety of round and oval sizes, order by pool size for a perfect fit.

In addition to the winch & cable to secure your pool cover, there are many winter cover accessories like Wall Bags, Cover Seal and Cover Clips that help to hold down a cover in high winds.

Air Pillows are used in to break up the ice sheet that forms in the pool under the cover, during several days of below freezing weather. This prevents damage to the pool walls and skimmer from a solid sheet of ice expanding outward.

intheswim leaf catcherIf your pool is surrounded by large beautiful trees, put the Leaf Catcher on top of your winter cover. Lightweight and super tough mesh lets you remove all leaves and debris in one easy motion. Worth its weight in gold if you have large trees, like I do – saved me from hours of messy leaf dredging each year.

One more winter pool cover accessory is worth mentioning. You’ll need some way to remove the rain water and snow melt from the cover, either with an electrical or gravity fed pool cover pump.

That’s it ~ 10 little steps to closing your aboveground pool. Your pool may be slightly different. If you have questions about how to close it, or what products are needed, you can call our pool winterization experts anytime at 1-800-288-7946!


Ayesha Aslam
InTheSwim Staff Blogger