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Unicel Cartridge Cleaning Instructions for Chlorine Users

When should a cartridge element be cleaned? For swimming pools, clean the cartridge when filter canister pressure reaches 8 PSI above the normal system or new cartridge starting pressure. If Baquacil is used as a sanitizer, the filter element must be cleaned with Baqua Clean before any cartridge cleaner is used.


What is the procedure to clean my cartridge?

  1. Remove the cartridge from the filter housing following the manufactures instruction.
  2. Use a garden hose with a straight flow nozzle to wash down the filter element. Work from the top down, holding the nozzle at a 45 degree angle, and wash all the pleats with emphasis between pleats.
  3. Rinse until all dirt and debris are gone.
  4. If the filter has a coating of algae, calcium carbonate, iron, or other minerals, soak the cartridge in a solution of one muriatic acid to twenty parts water until all bubbling stops. **WARNING** Use rubber gloves and safety glasses when using acid and chlorine. Do not add water to acid. Do not mix acid and chlorine.
  5. Rinse the cartridge clean and reassemble housing.



Question: How can I tell when a cartridge filter element needs to be replaced?

Answer: With no moving parts or electrical switches to fail, cartridge elements do not have a defined termination point. Instead the fine interstices of the media matrix gradually plug up over time. In a typical spa, the culprit that plugs the media is perspiration and body oils combined with soaps, chemicals and very fine particulate. In a swimming pool, the loading is primarily debris along with sun tan lotions and organic matter such as algae.

Assuming the filter is properly maintained and correctly sized to the pump, determining when the cartridge is exhausted depends primarily on three factors: 1) Shorter cycle time between cleanings; 2) Low water flow rate and high differential pressure; and 3) Catastrophic failure such as a tear in the media or center core collapse. All three are dependent upon proper pool or spa water chemistry and following a routine maintenance schedule. Homeowners should be reminded that filter elements are plastic and should be.