How to clean your pool filter

If you think about it, pool filters are the dirtiest parts of your pool. All of the water passes through your pool filters and they grab on to all of the dirt and debris so that the rest of your pool is clean and sparkly. Now, most of the questions we often get is how often should filters be cleaned and how to clean the filter properly.

The first step to answering those questions is to first determine the type of pool filter that you have installed on your pool.

Different Kinds of Pool Filters

There are three main types of pool filters. Each one has their own strengths and weaknesses, but assuming that you already have a pool, it’s more likely that you have one of the three filters installed on your pool.

  • Sand Filters – These are the easiest types of filters to maintain and pretty much the most cost-effective type of pool filters as the media only needs to be changed every five years or so. Sand filters capture and traps contaminants and debris down to the 20-30-micron size (a human hair is 70 microns across, so that should give you an idea of how small the particles that are being filtered out are)
  • Cartridge Filters – Cartridge filters use replaceable fabric-like well… cartridges as the filter medium. These types of filter produce clearer water than sand filters as they can capture and trap contaminants down to 10-20 microns in size. These are the most commonly recommended filter systems as replacing them is a breeze.
  • Diatomaceous Earth Filter – This filter is as hard to clean as it is to pronounce. Diatomaceous earth filters are the most effective types of filters as they can trap down to 3-5 microns in size. These are fairly uncommon in-home pools as they require a lot of maintenance work and checking to ensure that the unit does not get damaged.

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How often should you clean your pool filter

Here’s a quick and handy chart on when you should consider cleaning out your pool filter.

Filter System Type When to Clean the Filter

Sand Filters

Once a month, or when pressure gauge on the filter is 5-10 PSI higher than regular pressure. (Or depending on your gauge, around 80Kpa)

Cartridge Filters

A quick hosing down every two to three weeks and a thorough soak every couple of months.

Diatomaceous Earth Filter

Once a month or when pressure gauge on the filter unit is 5-10 PSI higher than regular pressure (Or depending on your gauge, around 80Kpa), plus annual dismantling to check individual parts. Fresh DE must also be added every time the filter is cleaned.

Different Pool Filters, Different Cleaning Methods

Now we’re at the heart of this post. How to clean your pool filter.

Sand Filters

Once you’ve determined that your sand filter is time for a thorough clean, it’s time to backwash it. The term for cleaning sand filter is called “backwashing”. If you take a look at your sand filter, you’ll find a multiple port system that has six settings. Filter, Backwash, Rinse, Circulate, Closed, and Waste.

Backwashing is a fairly simple process. Simply turn off the pool pump, set the multiport valve handle to “backwash”, let it run for two minutes (or until the glass viewport on the filter is clear). Turn off the pump, set the multiport valve handle to rinse and let it run for about a minute or two. Turn it off, set the multiport back to filter and turn the pump back on.

We also have a more in-depth guide on how to backwash your sand pool filter which you can check down below.

Also remember that you will need to change the sand in your sand pool filter every five years or so depending on the type of media that you’re using. For more information on changing the sand in your pool filter, check out our comprehensive guide to changing the sand in your sand pool filters.

Cartridge Filters

To make sure that your cartridge filter doesn’t get gummed up and get damaged prematurely, it is advisable to give them a quick hose down every two to three weeks. To do this, simply open up your cartridge filter housing and pull the filter out and give it a good hose down to remove dirt and debris. This process usually takes a few minutes and is pretty straightforward. But if you want to make it even easier, you can get a hose attachment like the Water TechniX Waterwand to cut the time needed and water used by 80%!

Every two or three months, you should also give your filters a good soak in some Water TechniX filter cleaning solution. Just mix the Water TechniX Filter cleaning solution with some water, drop the filter in and let it soak for about 12 hours (or overnight). After the filter is done luxuriating in its filter cleaner bath then give it a hose down to remove all of the remaining dirt and debris and it should be as good as new.

If after hosing down and soaking your cartridge filter doesn’t improve the filtration of your pool then it might be time to replace your filter. You can usually tell that your cartridge filter is in need of replacement when it’s discolored, mushy to the feel, has small holes and tears in it, or just basically a disheveled look to it. Replacing cartridge filters is a breeze, just take out the old ones and plop in your new filters and you should be good to go. Not sure what type of cartridge filter to get? Check out our article on how to correctly measure your pool filter down below.

Already know what to get? Hop on down directly to our store and browse all of the Pool Filter Cartridges we have on stock.

Diatomaceous Earth Filter

These are basically the same as sand filters, but on steroids. The media used is diatomaceous earth, or basically fossilized diatoms (plankton). To clean a DE filter, it must be backwashed like a regular sand filter. But unlike sand filters, DE filters spit out a lot of the diatomaceous earth media during backwashing, meaning that you’ll have to top-up with more filter media every time you clean your filter, which adds up to a lot of $$$ if you look at it on an annual basis.

DE Filters also have to be taken apart every year to be cleaned and degreased and to check that everything is working properly. Aside from that, Diatomaceous earth is ultra-fine, which requires special protective gear to handle. Some places around the world require special licenses and training to handle diatomaceous earth due to it being a possible health hazard. For us, all of these cons outweigh the pros and this is why we don’t recommend DE filters for home use.


Now that you know how to clean your pool filter, be sure to make a note somewhere visible so that you will have a visual reminder of when you should clean your pool filters. Regular pool filter maintenance will not only give you a cleaner pool, but this will prolong the life of your pool components as well, saving you money in the long run.

Do you have any questions about this topic or the featured products? No worries, we're here to help! Drop us a question down below and we'll get back to you ASAP.

Happy swimming :)

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