Winterizing Your Pool: How to Clean Your Pool Filter

22nd Sep 2023

If you live in a colder part of the globe, swim season may already be over. Time to think about winterizing your swimming pool. That means balancing the water, pulling up the ladder and getting your pool equipment ready to withstand the rigors of ice and snow.

One piece of equipment you’ll need to winterize is your pool filter. Your swimming pool filter has been keeping your pool water clean all season long, and now it requires some special attention.

Whether it's a sand filter, cartridge filter or DE (diatomaceous earth) filter, the following winterizing guidelines will help ensure it’s clean and ready for lots of pool activity next summer.

There are a few different types of pool filters and each kind requires slightly different care.

Sand Filters

Sand filters are popular for their straightforward maintenance. To winterize your sand pool filter, follow these steps:

Backwash and Rinse: Start by backwashing the filter to remove debris and contaminants. Run the pump for a few minutes or until the water in the sight glass appears clear. Then, switch the pump to "Rinse" mode and run for about 30 seconds.
Chemical Balance: Adjust the water's chemical balance by testing and adjusting pH, alkalinity and sanitizer levels. Balanced water helps prevent scale and corrosion during the winter.
Drain and Cover: Remove the drain plug from the filter tank to allow any excess water to drain out. Once drained, cover your sand filter and plumbing lines with a winter cover to protect them from the elements.

Cartridge Filters

Pool cartridge filters provide excellent filtration and are easy to clean. Here's how to winterize them:

Clean the Cartridge: Remove the cartridge from the filter housing and use a hose to thoroughly remove any debris from the filter pleats. For a complete cleaning, use a pool cartridge filter cleaner. Follow the instructions on the cleaner and submerge your filter in a properly prepared solution for about 24 hours. A bucket or garbage can works well for this step. Rinse and allow the cartridge filter to dry completely before storing it indoors for the winter. Replace cartridge filters that are crushed or torn.
Winter Cover: Make sure to cover the filter and plumbing lines with a winter drain cover to prevent freezing and damage.
Inspect O-rings and Seals: Take this opportunity to inspect the O-rings and seals on the filter housing. Lubricate them if necessary to keep them from drying out during the cold months. Replace them if they are worn, cracked or damaged.

DE Filters

A DE pool filter offers superior filtration., but requires a bit more attention. Here's how to winterize them:

Backwash and Rinse: Start by backwashing the filter to clean out debris. Then, rinse it to ensure any remaining DE powder is removed.
DE filters benefit from a 24 hour soak in pool filter cleaner or diluted muriatic acid. Pool filter degreasers and alkaline based filter cleaners also will do a good job. Remember, acid is corrosive. Acid washing your filter more than once a year could damage it and shorten its life.
Chemical Balance: Test and balance the pool water's chemistry to ensure it's within the recommended ranges. Balanced water prevents damage to filter components.
DE Grid Inspection: If your filter uses DE grids, remove and inspect them for damage. Clean them thoroughly with a hose and let them dry before storing indoors. Replace any damaged grids before closing up for winter.
Winter Cover: As with other filter types, cover the filter and plumbing lines adequately to shield them from winter weather.

General Tips and Tricks

Timing Matters: It's best to winterize your pool and filter before the first freeze hits. Freezing water can cause serious damage to your equipment.
Store Indoors: Whenever possible, store filter components indoors during the winter to protect them from extreme temperatures.
Label Your Parts: As you disassemble your filter components, consider labeling them to make reassembly a breeze come spring.
Professional Inspection: If you're unsure about any step, or if your pool has specific needs, consider hiring a professional pool service to winterize your pool filter.
Document Your Process: Take photos or notes as you disassemble and winterize your filter. These references will be valuable when it's time to get your pool up and running again.

Whether you’re a first-time pool owner or have several seasons of experience, disassembling and cleaning a pool filter system may seem intimidating. However, with the right steps, you can ensure your pool equipment weathers the cold months.

Whatever type of pool filter you use, proper care will help safeguard your investment and make opening your pool a breeze next season.

Remember, proper maintenance now means less hassle and more enjoyment when summer returns!