Swimming Pool Blog

How to Winterize an Above Ground Pool

by Rob Cox, August 7, 2018

How to Winterize an Above Ground Pool

time to winterize an above ground pool

With the end of summer drawing nearer, it's almost that time of year again - time to button up the pool and close 'er down! If you live in the snowbelt (anything above the blue line on the map below), there are certain procedures that must be done to avoid damage to the pump and filter equipment, protect the pool liner, and keep the water fresh and clean.

The procedure can be condensed to four specific areas, or the "Four Cs", as I call them: Clean, Chemicals, Cover and Close. Each of these steps should be done in the proper order to prevent duplication of efforts.

Sure, you can call a pool service company to come out and close the pool for you, or you can obtain the winter pool supplies needed and do the labor yourself! Save time and money this year by following these simple steps on cleaning and winterizing your own above ground swimming pool.us snow fall map


 1) Balance the Water

Properly balanced water has the correct pH, total alkalinity and calcium hardness levels. Raise or lower as needed to the proper levels (pH: 7.2-7.4, TA: 80-120ppm, Ca: 180-220). In addition, we want to close the pool with the water being as sanitary as possible. Remove any algae growth and shock the pool, following instructions to ensure proper dosage.

2) Clean the Pool & Add Winter Chemicals

Any organic debris that remains in the pool, whether it's large leaves or very small algae, will quickly consume the algaecide and other chemicals added to keep pool water fresh. Before covering the pool, do one last skim of the surface to remove as much debris as possible. If there are lots of leaves, it will help to use a leaf rake Also remove the pool cleaner and any ladders or steps remaining in the pool.

Add winter chemicals to keep the water fresh. Pool closing kits usually include pool shock, winter algaecide and a stain/scale preventer, as well as other bonus items. There are many above ground pool winter chemical kits to choose from, and they are packaged according to pool size in gallons. If you plan to use a chemical floater over the winter, be careful to not use chlorine tablets. These can sit up against a wall or sink to the bottom and bleach the vinyl liner.

3) Lower the Water Level & Insert Winter Plugs

Drain your above ground pool enough to get the water level 2-3" below the skimmer opening. However, lowering the water more than 12" from the top rail can cause problems. Water in the pool keeps the liner flexible and supports the pool walls. If your return fitting is at this level, you can remove the hose from the filter and allow the pool to drain to that level. Otherwise, allow the pool to drain to a couple inches below the skimmer faceplate, then use a threaded plug to close off the return on the pool side, or you can use expandable plugs on either side.

Use a skimmer guard or gizzmo to block the hole in the bottom of the skimmer and absorb any ice expansion. Or, if equipment is removed, you can leave the skimmer unplugged so any water that spills in will simply drain out onto the ground. Many above ground pool owners use a skimmer plug, which is basically a Tupperware lid for your skimmer. Just snap the plug into your existing skimmer faceplate, and your skimmer is sealed for the winter. No pool draining required!

4) Cover the Pool Tightly

Use cover clips or cover seal to keep high winds from getting up under the cover and blowing it off the side (BIG problem). Make sure to patch any holes in the cover so rain and snowmelt won't mix with your pool water. Using an air pillow serves two purposes under the solid cover; it will lift up the cover in the middle and keep excess rain from puddling, and it also serves as an ice equalizer to keep the ice sheet in the pool from freezing too solidly across the pool and damaging the walls.

Keeping the cover tight and clean during the winter is a regular chore. Make sure to check on the cover regularly over the winter, and remove debris that may clog your cover pump or puncture the cover. In lieu of electric pool cover pumps, you can use gravity or siphon pumps to remove the rain water and snow melt. Keeping the cover as dry as possible is recommended to prevent water contamination.

If your aboveground pool has a complete surround deck, you may find it easier to use water bags or aquabloks to secure the cover to the deck, instead of the normal cable/winch arrangement for fitting the above ground pool cover.

5) Remove the Pump and Filter System

Remove and drain the pump and filter completely. If you have a DE or cartridge type pool filter, remove the elements and hose thoroughly, allowing them to dry before installing back into the filter tank. Place them in an area where they won't be disturbed during the winter, storing them indoors if possible. If you have a chlorinator, make sure that all tablets are removed during the winter. Pool heaters or other equipment? Remove the drain plugs on the sides or bottom, and make sure all water is drained to prevent freezing damage. 


That's pretty much all there is to it! Each pool may have small differences to the above information. However, the basic process is essentially the same. It's simple enough that anyone can do it and save themselves a few bucks on closing expenses.