How to Use a Pool Cartridge Filter System

person removing a pool filter

For your above-ground or in-ground pool, a cartridge filter system has advantages, including low cost, compared to the large canister sand and DE filters. Plus they are easy to maintain. The cartridge filter system also has a large filtering area, between 100 and 300 square feet.

Most other pool filters have up to 50 square feet of filtering medium. The cartridge filter can process high volumes of water so it needs changing and cleaning less often. Another measure of filter effectiveness is particle size filtration. Cartridge filters can strain out smaller pieces of debris and contaminants than a sand filter, but not as tiny as those a DE filter can trap.

You can purchase cartridge filter replacements at national hardware stores and at specialized pool equipment retailers. Follow the directions below for installing and operating a cartridge filter system for your swimming pool.

Note - This installation should be done by a trained pool technician to protect your warranty. Here is what you should watch for as it is being done.

Step 1 - Install the Cartridge Filter System

Choose a location where the pool filter unit will sit, below the highest water level of the pool. This ensures water will flow correctly to and from the filter. Identify all hoses, pipes, and cartridge holders and assemble the unit according to the directions on the package. Attach the intake, outflow, and waste water hoses and connect them to the correct pipes on the swimming pool. Insert the cartridge (or cartridges if a multiple unit) into the filter unit.

Step 2 - Prime the Pool Cartridge Filter Unit

inside view of pool filter

Prime the filter by loosening the top until the reservoir fills with water. Tighten the top to close it and turn on the filter's electricity to check that it will run properly.

Step 3 - How often to Run the Pool Cartridge Filter System

Allow the filter to run every time people are in the pool. Run the filter for a few minutes every day before anyone swims in the pool. Your particular filter's directions will tell you whether the filter should be running while you are vacuuming the pool; some vacuum models pump out debris directly through the wastewater pipe.

Step 4 - How Often to Clean the Cartridge

Check the normal running pressure of the filter unit, on a gauge atop the filter unit. Normal pressure is usually 12 pounds. As the filter accumulates dirt and debris, the pressure will rise. Once the gauge shows 10 pounds higher than normal, clean and rinse the cartridge.

Step 5 - How to Clean and Rinse the Cartridge

hosing down a dirty pool filter

Turn off the filter unit. Open the top and take out the cartridge. If you have more than one cartridge, do them one at a time. Using a hose with a sprayer, spray the filtering vanes of the cartridge thoroughly. Check that all dirt and particles you can see have been swept out. Avoid high pressure sprayers as these will damage the vanes. Dip the cartridge in a weak solution of trisodium phosphate to release oils from tanning and sunscreen products.