Swimming Pool Blog


10 Steps for Closing Your Swimming Pool

10 Steps for Closing Your Swimming Pool

by Rob Cox, September 6, 2018

10 Steps for Closing Your Swimming Pool

winterizing a pool infographic

Winterizing your own swimming pool, or thinking seriously about it? Sure, you can hire a local company to button things up for the season. OR you can save some money and close the pool yourself. Winter pool closing steps must be done in a very specific order to ensure an easy pool opening the following spring. Follow the guidelines below to close your own swimming pool this winter!

1. Remove ladders and accessories.

Loosen the ladder anchor socket bolt. When it rises about 1/2 inch, knock it down with a heavy wrench. Wiggle the ladder loose so the pool cover will fit properly. Most ladders can be stored outside, but plastic steps may do better if stored inside. Also remove any handrails, fill spouts, eyeball fittings, pool cleaners and skimmer baskets. Store in a safe place where you can easily find them again in the spring.

2. Balance your water chemistry.

It's important to start winterizing with balanced pool water. Start with pH, and adjust within the 7.2-7.4 range using pH Up or pH Down chemicals.Total alkalinity should be in the 80-120 ppm range, and calcium hardness should be around 180-220 ppm. The pool should also be free of any visible algae and be as clean and clear as possible. This step should be completed about a week before closing the pool so the chemicals have time to properly disperse.

3. Clean the pool.

Skim, vacuum and brush the pool thoroughly, in that order. This is technically step #4 in the graphic above, but vacuuming the pool can be difficult when the water level is below the skimmer. The pool should be spotless when you cover it. Remove every bit of organic matter possible, and give the pool one final skim (if necessary) before covering it for the winter. A couple days before adding your winter chemicals, you'll also want to shock the pool. See step #6 for more details.

4. Lower the water level.

Lower the water level in your pool according to the guidelines below.

If you have an inground pool with a mesh safety cover, lower the water level between 6-12" below the bottom of the tile. If it's a solid cover, you can just have the water be a few inches below the skimmer. With any safety pool cover, never lower the water more than 18" from the top of the pool, or top of the coping stone or pool edge. Doing so can increase stress on your safety cover and cause the cover to rip or pull the anchors out of your deck..

If you are using a solid winter pool cover (one that floats on the surface and is held in place by water weights), lower the water level 3-4" below the bottom of the skimmer opening. The exception to this is if you are using a skimmer plug across the front of the skimmer opening. Working almost like a Tupperware lid for your skimmer, a skimmer plug will seal water out of your skimmer and allow you to keep the water at normal operating levels during winter.

Above ground pools should also have the water lowered no more than 3-4" below the skimmer. If too much water is removed or if water leaks out during the winter, the cover could fall in. Even worse, the liner can relax and wrinkle, or the walls could collapse inward.

5. Turn off the heater.

If your heater is a millivolt style with a continuous pilot, turn off the pilot. Shut off the gas supply to the heater, and turn the gas valve to the OFF position. On gas heaters with pressure switches hanging down (Laars style) connected to a siphon loop, disconnect the pressure switch to drain the copper tubing. Open the drain plugs on both intake and outlet headers, making sure your heater is drained completely of pool water.

If you have a timer clock for your pool pump, turn it off by removing the timer dogs. Disconnect power to any other electrical components that you don't want to operate during the winter.

6. Add your winter closing kit chemicals.

For this step, we highly recommend using a chlorine-free pool closing kit. These kits come with everything you need, and are packaged according to the size of your pool. They include chlorine-free pool shock, a strong winter algaecide, a stain and scale preventer, a slow-release floater with oxidizing chemicals, and some closing kits even include extras to help keep your pool in top shape through the off-season. Purchasing a package of these items is much cheaper than buying each individual product on its own, and and a pre-measured kit helps take the guesswork out of adding chemicals to your pool. Follow instructions on your winter kit, or if using your own granular chlorine, be sure to shock several days prior to closing.  Shocking the pool just before adding algaecide can be a problem - the high chlorine levels can break apart the polymer chains in your algaecide and render it useless.

If you are not using a winter closing kit, just be careful when using chlorine floaters. They can sink, tip over or get stuck next to a wall, which will stain a pool's vinyl or plaster surfaces during the winter. Use a high quality winter algaecide, a stain and scale preventor (chelator or sequestering agent) and some form of oxidizer to winterize your pool.

7. Drain water from pump and filter.

DE filters should be opened up, and the filter grids should be hosed clean and inspected for rips or tears (mild staining is usually OK). Cartridge filters should have the cartridge removed and cleaned thoroughly. In both cases, after cleaning, reinstall the filter media back into the tank for winter storage. Lubricate any filter o-rings you come across in the process.

Adding antifreeze to your pump can damage the pump seal, so this should be avoided at all costs. It's much better to completely drain all of the water from the pump and filter system, including the chlorinator and heater, or any other pool equipment containing water.

8. Blow out the water lines.

The very best way to avoid pool closing problems from freeze damage is to "blow the lines" using a small air compressor at low psi or using a high volume blower like a Cyclone vacuum/blower or a powerful shop vac. Blow air through all equipment and pipes, both to and from the pool, and use pool plugs to prevent water from flowing back into the return lines. You'll also want to install a skimmer guard to absorb the pressure of expanding ice and keep your skimmer from cracking. If you want to add non-toxic pool antifreeze to the lines for added peace of mind, now is the time to do it.

9. Fill water bags or bring up safety cover anchors.

Safety covers will have a series of anchors around the pool, which are recessed flush against the pool deck while the pool is in use. Use an anchor tool to twist the anchors and bring them up to the surface.

If you are using a solid winter pool cover that requires water weights to hold it in place on the pool deck, fill the water bags where they will lay. If filled elsewhere, be careful not to drag or drop the water bags as they are moved around the pool. Fill bags only 80% full to allow for expansion as the water freezes. Keeping several small pails or pans of water around the pool is a good idea to keep birds and critters from poking holes in the pool water bags for a drink. If you're wanting something a little more durable than thin water tubes, you can also try using a product like Aqua Bloks, which will hold up to many years of use.

Above ground pools should use an air pillow, also called a pool pillow or an ice equalizer pillow, to absorb the expansion of the ice and prevent the ice sheet on the surface from putting pressure on the pool walls. Go ahead and inflate the pillow - about 60-80% will be sufficient.

10. Cover the pool.

Skim the pool once more if needed. The pool should be as clean as possible! Also make sure that the pool cover is clean. If you spread a dirty cover across the pool that you just cleaned and winterized, you may be in for a mess come springtime. As you spread the cover over the pool, inspect closely for tears or rips. If possible, move these problem areas to the deck or close to the edge. You won't want to put the cover pump in those areas - you'll end up pumping your pool water out of the pool through the holes in the cover. The water level will drop, and the cover falls in...it's a big mess, so don't do it. Apply cover patches as needed - there are poly patches for solid winter covers and mesh or solid patches for safety covers. Secure the cover with water weights (inground winter cover), straps and anchors (safety cover) or a cable-&-winch assembly (above ground winter cover), depending on the type of pool cover you're using.

That's all there is to it! Keep an eye on the pool cover during the winter. Keep it as clean and dry as possible, and adjust as needed to keep it secure. Remember that solid pool covers with water bags are not safety pool covers, and can be very dangerous for kids or adults who accidentally fall on top off them. Restrict access to the pool area during the winter and keep an eye on the kids!