BioLab Info

THE CARTRIDGE FILTER

How it Works

A cartridge filter uses a synthetic fabric as the filtering media to sift particles of debris from the water. Reemay™ is one of the more popular fabrics used today in cartridge filter elements. More durable than the paper cartridges, which were once used, these new synthetic fabrics have a much longer life. If they are properly cleaned and cared for, the cartridge can last approximately two to three years.

The cartridge fabric is formed into vertical pleats to maximize the surface area of fabric available for filtering within the smallest amount of space. Most cartridges for swimming pools will contain anywhere from 100 to 200 square feet or more of filter surface area. Most cartridges for spas will contain approximately 50 to 100 square feet of filter area. (NOTE FROM POOL EMPORIUM, INC.: The more filter surface area the better, but we have many customers who have as little as 50 square feet of filter surface area on a pool, and as little as 25 square feet of filter surface area on a spa. However, it is important to note that while there is no such thing as a having a filter that is too large, there are serious consequences to having a filter that is too small; especially if it is sized smaller than the flow rate of the pump.)

Advantages

There are several reasons a pool owner might choose a cartridge filter:

Removes particles as small as 10 to 15 microns
Mid-priced option
No backwashing - saves water

Cleaning the Cartridge Filter Element

Particles (dirt, dead algae, etc.) captured in the filter pleats build up over time and the filter works less efficiently. The build-up of debris makes it more difficult for the water to pass through the filter element which causes the filter pressure to rise. An increase of 10 to 15 psi over normal, clean operating pressure tells you that it's time to clean the filter. An increase of 10 to 15 psi over normal, clean operating pressure tells you that it's time to clean the filter. (Note from Pool Emporium, Inc.: Our experience in Florida has shown that most pools do not reach a pressure increase of 10-15 psi, but are in need of cleaning. We suggest cleaning your filter at an increase of 3-5 psi or every two weeks, whichever comes first.)

There are two steps necessary to cleaning a cartridge filter (or any filter for that matter):

1. Physical cleaning to remove the loose debris.
2. Chemical cleaning to remove greases, oils, and scale.

Physical cleaning should be done when filter pressure rises 10-15 psi above normal, clean filter pressure (Please see Pool Emporium, Inc. note above). Use a garden hose with a nozzle. Do not use a pressure washer hose! The water pressure from a pressure washer is actually too strong and will destroy the fabric, making it less porous and less able to capture particles. A garden hose has the right amount of pressure to remove the loose debris without damaging the fabric. Rinsing a cartridge filter with a garden hose is a relatively simply task, but it is time consuming.

Chemical cleaning is absolutely essential in order to maximize the life and efficiency of the cartridge filter. Three BioGuard products are designed for chemically cleaning the filter.

For a chlorine or bromine treated pool or spa Strip Kwik™ is used to remove greases and oils, and then Kleen-lt™ is used (after the Strip Kwik treatment) to remove calcium scale deposits. (NOTE FROM POOL EMPORIUM, INC.: We do not suggest using Kleen-It™ on your filter unless it is necessary. Doing so will more permanently set any oils that have not been completely removed by a thorough cleaning. You may test your filter to see if it needs this second step by placing a few drops of acid on the pleats. If it bubbles, use the Kleen-It™, if it doesn't don't!) For best results and longer filter life, rinse the chemically cleaned filter thoroughly and allow it to dry before returning it to service. (Pool Emporium, Inc. suggests you chemically clean your cartridge filter 2-3 times per year, depending on pool environment and usage.)

We suggest you buy two cartridges for your filter. While one cartridge is being cleaned, the other can be used in the filter, and you can continue to use the pool or spa.

For a SoftSwim® treated pool SoftSwim® Filter Cleaner® is specifically formulated to dissolve the routine accumulation of debris normally associated with biguanide (SoftSwim) chemistry. Chemical cleaning of a filter cartridge on a SoftSwim pool should be done every four to six weeks.

Failure to perform routine chemical cleaning of the filter may result in problems and additional expense (and frustration) for the pool owner.

Replacing the Cartridge

Depending on how often the cartridge has been chemically cleaned, the fabric in the cartridge will have deteriorated and/or plugged up. Filter pressure will usually remain high (over 10 psi above normal pressure when new) even after cleaning. At this point, the cartridge filter needs to be replaced. An additional symptom of a plugged-up filter is a low or weak flow of water from the pool or spa return inlets. If the element is not replaced, problems associated with poor circulation and poor filtration will begin to show.