When Does My Pool Filter Need Cleaning?

I have a swimming pool that uses cartridge filters. How often should I clean the swimming pool filters?

The answer can vary from filter to filter, but a general guideline on any swimming pool filter is to take a reading when the filter is clean, then clean the pool filter when the pressure rises about 10 psi.

As the filter (cartridge, sand or DE) becomes "clogged" with debris, two things happen:

• the back pressure on the filter system rises

• the overall flow rate of the swimming pool circulation system drops

One of the most important factors of a cartridge filter operation is that there not be too much flow through the filter.

Too much flow significantly decreases the cartridge life and lowers the efficiency of the filter(stuff gets through the filter and goes back into the swimming pool).

Proper cleaning of your filter cartridges will not only help to keep your pool as clean as possible, but also increase it’s useful life.

Eventually, the cartridge will have to be replaced. Dirt, oils and minerals build up which cleaning won’t remove.

Here are some tips for when/how to clean a pool filter cartridge, and when to pronounce your filter cartridge’s useful life as complete.

When to Clean a Pool Filter Cartridge

Filter cartridges should be cleaned whenever the filter pressure gauge increases by about 8 PSI (pounds per square inch) or more above the normal operating pressure, or at least every 6 months assuming your filter is properly sized and you haven’t had any unusually large burden placed on the filter (such as a bad algae bloom or very heavy bather loads). If you notice a change in your water quality, inspect the filter for damage/tears, and a cleaning may be needed.

When to Replace a Filter Cartridge

Generally most people replace their filter cartridges about every 3-5 years, but don’t use the amount of time that has passed as the only determining factor, monitor the performance of your filter. Your time frame may be longer or shorter depending on the demand placed on the cartridge.

There are 3 ways to determine when your filter cartridge has given up. 

1. Pool filter cartridges need to be cleaned when the pressure gauge rises 8 PSI above normal operating pressure. When the time frame in between this increase in pressure begins to shorten significantly, the filter cartridge probably needs to be replaced.

Keep track of the filter pressure and the date you clean your filter cartridge. When the length of time between cleanings is half of what it used to be, your filter cartridge has reached it’s “half-life”, and it’s time to replace.

2.  Another way to determine if your filter cartridge is terminally ill, is when you notice that the water stays cloudy or green despite proper chemical balance, or that you have to run your filter longer or use more sanitizer, to achieve clean and clear pool water.

Clean the cartridge first, but if the problem doesn’t clear up in a few days, the cartridge is probably unable to filter the water as effectively as it once did. Time for a new one.

3. The third way of determining cartridge mortality is to inspect it thoroughly every time you clean it, looking for rips or tears in the fabric. Damage to the filter will reduce the potential for sufficient filtering. If you have tears, or rips in the fabric, or if there are cracks in the end of the cartridge; it needs to be replaced.

Need a filter clean, or have any questions about how you can start weekly cleaning? Visit The Blue Lagoons !

Happy Swimming!