Winterizing your pool: active and passive winterizing

Active or passive winterizing?

There are two ways for a pool to get through the winter. The choice depends mainly on whether your area gets frost and whether you will be nearby to keep an eye on it.

Passive winterizing step by step

1. Clean thoroughly. Net, brush, vacuum. Anything left on the floor will have turned into a stain by spring.
2. Balance the chemistry one last time. pH at 7.2–7.6 and a shock chlorination, with circulation running for at least a day.
3. Add a winterizing product, if you use one, at the dose on the packaging, with the pump running so it is distributed.
4. Clean the filter with a backwash and rinse.
5. Lower the water level below the skimmer openings.
6. Drain the pipework, pump and filter through the drain plugs, and set the multiport valve to the position its manufacturer specifies for winter.
7. Place ice compensation floats in the water, tied so they stay in place.
8. Spread out and secure the winter cover.

Active winterizing: what changes

The water level stays at normal height and the pump runs on a timer for far fewer hours than in summer, since cold water uses little chlorine and doesn't favor algae. You'll find guidance on the hours in how many hours to run the pump. Test pH and chlorine every one to two weeks and empty the baskets after wind and rain.

A cover helps here too, because it keeps leaves out. If the forecast shows frost, circulation must run during the cold hours so that water doesn't freeze inside the pipes.

Areas with frost

In mountainous and northern areas, ice is the biggest risk. Water left in a pipe, a pump housing or a filter can crack them when it freezes. That is why passive winterizing is the rule there:

• drain every point that holds water, and keep the plugs somewhere you will find them in spring,
• the floats absorb the pressure that a sheet of ice puts on the walls,
• if the plant room is not protected from the cold, ask your technician which components are worth disconnecting and storing indoors.

Don't drain the pool to save yourself the winter care: the liner needs the weight of the water to stay in place. See why we don't drain the pool.

What to check during the winter

• The cover: water and leaves collecting on it and weighing it down, and the cords and fixings after storms.
• The water level: after heavy rain it can rise back up to the skimmers; if so, lower it again.
• The plant room: damp, water on the floor, animals that have taken shelter.

For a holiday home that stays closed all winter, organize the checks as we describe in remote pool maintenance. When spring comes, opening the pool is simple if it was closed properly.

Questions

See also