How to close your swimming pool and keep it in good condition

Closing the pool for the winter is on the agenda of many Quebecers in the fall! Here are some practical tips on the subject. These tips will help reduce your expenses, save you time, limit the use of polluting chemicals and extend the life of your pool.

In addition to these tips, you should know that there are complete guides on in-ground and above-ground, pools, including those from the Association des Commerçants de Piscine du Québec.

When do we proceed?

There’s no point in getting ahead of schedule to close your pool: wait until mid-October, more or less, depending on the region.


One day before closing, get a head start:

  • Vacuum the pool.
  • Do a backwash.
  • Balance the pH of the water.
  • Do a final chlorine treatment and exceed the regular dose. If you have a salt system, increase the intensity of the treatment.

Tip: Since the water is clean and cold at this time of year, increasing the chlorine dose should provide the desired disinfection. This tip will save you the cost of a shock treatment! Pool chlorination products contain the same ingredient (calcium hypochlorite) as shock treatment kits, in a lower concentration. You only need to increase the dose to obtain a comparable result.

Now you are ready for closure and other related tasks!

Liner cleaning

To remove a ring on the liner, visible near the edge of the pool, simply rub with a damp cloth. Do not use a cleaning product so as not to alter the chemical balance of the water.

If you have a solar cover, remove it from the pool, then lay it on the ground to be washed with a gentle spray from a garden hose. Once the cover is dry, fold it up and store it away from the rain and sun.

Lowering the Water Level

When using the drainage function, lower the pool level by about 30 cm below the backflow. Also, don’t forget to remove the return water heads; to do so, simply unscrew the nuts.

Pipe drainage and frost "management"

Emptying the pipes of an aboveground pool is simple: just disconnect them, and gravity will do the rest.

However, since the pipes of an in-ground pool are buried, a shop vacuum or leaf blower will be useful. Here’s how it’s done:

  • Connect the unit to the first return hose you disconnect.
  • Temporarily seal the connection with duct tape.
  • Set the unit to "blower" and start. As the air pushes in, all the water in the hose will gush out at the other end of the return water pipe, like a geyser.
  • Maintain pressure until no more water comes out.
  • This will drain all the hoses.

Even if the hose connecting the pump to the skimmer is empty, act preventively:

  • From the skimmer, pour about ¼ gallons of antifreeze.
  • Push a foam cylinder (those usually sold as weather stripping) down the entire length of the skimmer. If it freezes, the ice will compress the foam rather than press against the walls of the pipe.
  • Close the opening.

An in-ground pool remains vulnerable to infiltration. To prevent them, screw plugs at the end of the water returns. Seal the plug by covering the threads with Teflon tape. This is an important precaution: fall rains or thaw can cause the water level to rise above them and even up to the skimmer.

In the case of a pool equipped with a bottom drain, the pipe connecting the bottom drain to the skimmer remains filled with water at the same level as the pool basin. Protect this pipe from freezing with the same method described above:

  • Pour antifreeze (approximately ¾ gallon in this case).
  • Insert a foam cylinder inside the hose.
  • Close the skimmer valve.

Tip for double skimmer protection

Since water and ice can rise, don’t let them get into the skimmer! Get polystyrene blocks from a swimming pool supplier that are designed to block the skimmer. Insert a first rectangular block at the bottom, then slide the second, cut to occupy the entire upper part.

Tip: poke one or two pins through the blocks to hold them together.

Storage of the pump and winterization of the filter

When the hoses are removed, and the power supply wire is disconnected:

  • Remove water from the pump and clean the basket if needed.
  • Store the pump in a frost-free place.
  • Empty the filter bottle and adjust the handle to "winterize".

Once the water has drained, do not replace the cap.

Winter cover and other precautions

Pool liners left uncovered can be damaged by UV rays. Due to their high cost (especially in an in-ground pool), take every precaution to prolong their life! Cover the pool with a winter cover until spring.

  • Over an in-ground pool, lay the liner flat and secure it with stakes driven into the ground.
  • Around an above-ground pool, use a system of cables and tensioners to hold the cover around the pool perimeter.

Impromptu visits

Animals sometimes venture onto the pool covers, fall in the water and remain trapped in the pool until they are exhausted. These stray walkers would like to find their way out!

Tip: To prevent this problem, place a board diagonally to allow them to climb to the edge of the pool. Remove the board at the beginning of the freezing period.

Fall of Leaves

Do you have many leafy trees on your property? Stretch a net over the winter cover for the leaf-fall period, then remove it when it’s done.

Tip: To keep the net out of the water, insert a balloon between the net and the pool cover. This will allow the leaves to dry and make it easier to pick them up.

If you don’t use a net, be sure to remove the leaves in late fall. Otherwise they will decompose, and it will make it very difficult to restore water quality in the spring. Some people have learned the hard way... However, with a few precautions, your pool will be ready to be used again when the sun comes out!

Source : https://www.caaquebec.com/fr/a-la-maison/conseils/capsules-conseils/conseil/show/sujet/comment-fermer-la-piscine-et-la-garder-en-bon-etat/