How to close a swimming pool? Best insights

Closing a pool can be the same as monthly maintenance but with more intensity and a few extra steps. Don’t be afraid to do it yourself, here we will tell you how to close a swimming pool.

How much does it cost to close a swimming pool?

The average price, excluding the pool closing kit and labor, is about $250, on the inexpensive side it can be around $150, and as far as $400.

Closing a swimming pool is not as difficult as it seems, it is just to increase the levels of cleaning and disinfection so that algae does not reproduce or generate incrustations in the pool. You can hire pool maintenance experts but it is maintenance that can easily be done by you.

How do you close a pool for winter?

Clean the pool of leaves and debris

A good cleaning before starting to close the pool is important because it avoids the proliferation of bacteria or microorganisms that can be harmful to your health. Even a clean pool prevents clogging of the filtration system. You just need to do a normal cleaning of your pool, adding a little diligence in removing dirt and debris.

Brush the pool carefully to remove dirt on the sides and bottom. Scrub vigorously if it has accumulated. Clean the skimmer ridge.

Test and balance the pool water

You do this routinely when your pool is due for maintenance. Make sure the water is well balanced, check the pH between 7.2 and 7.6 and the alkalinity of the water between 80 and 120 ppm (parts per million), and the calcium hardness between 180 and 200 ppm before closing the pool for the season.

Add additives and chemicals to winterize the pool

This step can be done for both summer and winter. It is to balance the water levels and add the appropriate chemicals to keep the pool water clean and crystal clear during the entire time out of service. This ensures that there is no bacteria or scale development while the pool is closed.

This starts a week before you are going to stop using it, add a phosphate remover (if you have a pool, you already know that phosphates promote algae growth). Anti-stain and anti-limescale chemicals prevent metal and mineral buildup in the water.

Shock and chlorinate the pool

Even if you see the pool water clean and clear, add a super chlorinator, which is commonly referred to as pool shock. It must contain at least 65% sodium hypochlorite to use. Usually, a pound bag is enough for 10000 gallons of water, dissolve the contents with some water from the same pool and once dissolved, pour the mixture into the pool.

Wait until the total chlorine level returns to between 1 and 3 ppm. This will take a few days and then add an algaecide as an additional measure to keep those tiny green pool worms at bay during the cold months and in the summer as well. Again, choose a product designed for enclosed pools. The amount to use varies with the volume of the pool; follow the algaecide manufacturer’s instructions.

Pool closure kits are now available that include all of these chemicals to stabilize pool water chemistry.

Lower the pool water level

If your pool water is in danger of freezing, depending on your location, it is mandatory to lower the water level before closing the pool for the season. In warm climates this does not happen, so you do not have to worry about this.

The exact water level depends on the pool cover. Those with mesh covers should make sure the water level is between 12 and 18 inches below the skimmer, while those with solid covers should aim for the water level to be between 3 and 6 inches below the tile. 

For an in-ground pool, run the filter or use a siphon pump to lower the water level. For an above-ground pool, it is not necessary to lower the water level. Simply remove the outlet hose from the skimmer basket.

During the winter, after draining the water to the suggested levels, put antifreeze in the skimmer opening to prevent water from freezing in the pool plumbing. Most pools require approximately 1 gallon of antifreeze to ensure the pipes are protected.

Clean and backwash the pool filter and pump

If you have a sand filter, it should be backwashed, turn off the pool heater first. Turn off the filter, then choose the multi-port filter valve setting that is labeled “backwash” or “drain to waste”. Some filtration systems are already connected to a waste collection receptacle, while others require you to connect a backwash hose leading to a waste disposal location. Turn the filter on and let it run for 3 to 5 minutes until the water comes out clean. Turn the multiport filter valve to the rinse position and let it run for 30 seconds before turning the filtration system off.

If you have a removable filter instead, remove it and clean it thoroughly.

Clean the pool pump lines

In winter, residual water can freeze inside the pool equipment and in the water lines causing them to expand and crack. It should be as dry as possible to avoid damaging the air compressor. If it is impossible (or very uncomfortable), you can avoid ice-related problems with pool antifreeze.

The draining process is simpler for aboveground pools: Remove all hoses and remove the plug from the bottom of the filter. Aboveground pool owners are encouraged to use a pool pillow. Placed in the center of the pool and tied to its sides, these air-filled rings help keep the water in the pool from freezing.

Remove all pool accessories

Remove all pool accessories, such as ladders and diving boards. This is just to ensure that the cover is securely in place. It’s time to remove the skimmer baskets and other pool wall accessories.

Before putting them away, clean all the accessories thoroughly and let them dry on a clean surface. Store ladders, diving boards, and other peripherals in a clean, dry place during the off-season.

Install a winter cover

This step is essential to keep a pool clean and clear while not in use. Two types of mesh covers are more affordable and require no maintenance but allow debris to enter the pool water.

Solid covers need a pump to remove rainwater and melted snow from the top. A solid cover that stays in place should keep the pool water clean underneath. Take precautions such as locking pool fence gates to prevent children from drowning due to water pooling on the draining cover.

Check the chemical composition of your pool monthly

During the winter, it is still important to constantly adjust and monitor the chemical balance of your pool. This is the same as what you do during the off-season, adding the necessary chemicals.

This same procedure applies to how to close a swimming pool in other seasons such as summer.

Can I just shock my pool to close it?

Yes, it is possible to over shock a pool. “Shock” is just a concentrated version of chlorine, and if used in excess it can cloud the pool water. If you use too much chlorine, avoid swimming in the pool until the water clears. Remove the cover, if you have one, to speed up the process.

Closing a pool is not as difficult as it seems, it is just to increase the levels of cleaning and disinfection so that algae does not reproduce or generate incrustations in the pool. You can hire experts in pool maintenance but it is easier and proudly how to close a swimming pool done by you.

Written by Vanessa Gallanti. October 23, 2023

Enthusiast about planning, project management, construction materials and technology, and construction. A civil engineer from Los Andes University and a content writer for Kukun.