How to prepare your swimming pool in France for the upcoming winter

Swimming pool trade bodies in France are recommending pool owners use “active winterisation” as a way of saving water this year.

Traditionally, swimming pools are “put to bed” for winter with all the pumps and filtration switched off and the pool covered.

Pipes and systems which could be drained were, to avoid the risk of water freezing in them. 

This meant that when the pool was opened in the spring, it took a lot of filtering and washing before the water became clear.

Ice prevention

Under the new system a cover is still used but the pool’s filtration system is run every day – albeit only for a few hours – and especially if temperatures are expected to drop below zero.

The movement of water through the system stops ice from forming, and the short filtrations mean it is usually easier to start up the pool when the warm weather returns.

Active winterisation still requires a good scrub of the pool at the end of the season but avoids emptying it completely for cleaning.

Read more: How to wake up your swimming pool when temperatures get warmer

The Fédération des professionnels de la piscine recently launched a calculator on its propiscines.fr website to help owners calculate the water consumption of a pool according to its layout, and learn how to reduce it.

“The calculator shows, for example, that a 4m x 8m pool uses an average of just 7m3 of water when it is actively winterised,” it said in a press release. 

This is in contrast to passive wintering, which at the start of the season requires the partial renewal of at least a third of the pool's volume.

The temperature of pool water should fall below 12C before partial filtration is started.

A chemical “winterisation” treatment – mainly a fungicide and water softener – should be poured in and regular water treatment stopped, with the only checks to make sure the pH is at recommended levels.

Read more: Stop stigmatising us during droughts, say pool owners in France