The Importance of a Clean Pool Filter, Procedures, and Best Practices

Learn about the importance of maintaining clean pool filter and its proper cleaning procedures. Let’s get into it!

Do you ever notice that bulky-looking tank in your pump or near your pool? That tank which has a lot of pipes and valves connected to it?

“Don’t judge a book by its cover.” Like what this famous quote implies. This unassuming-looking piece of equipment is your pool filter which plays a vital role in keeping your pool clean and hygienic.

In this article, we will be talking about the importance of keeping clean pool filter and the proper cleaning procedures. Let’s get into it!

Clean Pool Filter

Why You Need to Clean Your Pool Filter

If the pool pump is like the heart of your pool system, then your pool filter represents the kidney. As the pump moves the water into the filtration system, it creates pressure that forces the water into the filter system. 

The pool filter is composed of a tightly packed material that traps dirt and debris in the circulating pool water. Due to this continuous filtering, the water in the pool remains clear and clean which you will surely enjoy.

But filters only trap these dirt, debris, and contaminants, so over time, these will accumulate resulting in a dirty pool filter. This is the reason why you should clean a pool filter.

To further emphasize the importance of pool filter cleaning, the Centers for Disease Control and Prevention (CDC) includes cleaning of the pool filtration system to decrease the chance of contracting water illnesses. [1]

Aside from health reasons, regular cleaning of pool filters maintains efficiency and prolongs the service life of your pumps. If you think about it critically, as the debris and particles accumulate on the pool filters, more work is required from the pool pump to generate enough water pressure. This results in more power consumed and an increase in the wear and tear of the pump’s moving parts

Now that we’ve established the importance of why you should clean a pool filter, let’s now talk about how often you should clean a pool filter.

How Often Should A Pool Filter Be Cleaned?

There are several factors that affect the cleaning frequency needed for pool filters. The first factor that you should consider is the frequency of pool usage and the number of regular users. More swimmers result in more debris and other contaminants mixing into the water. Which will ultimately end up stuck in your pool filters.

The second factor is your environment and location. If your pool is in a location that has an environment that is very dusty and windy, you might need to increase the frequency of cleaning. These environmental factors increase the rate at which dust and debris gather in your pool.

And the last factor is the type of pool filter that you are using. Usually, pool cleaning is only associated with a cartridge pool filter since sand filters and DE filters have backwashing options. We’ll get more into that later.

Let’s discuss first the signs to look out for which tells you if you need to increase the pool filter cleaning frequency.

Clean Pool Filter - signs to look out for which tells you if you need to increase the pool filter cleaning frequency.

Signs That You Need To Clean Your Pool Filter

With all the factors that you need to consider, it might feel a little bit confusing to point out if it’s time to clean the pool. But fear not, we got you covered. 

The first and major sign that you need to clean your pool filter is an increase in the reading of the pressure gauge that measures filter pressure. Normally, the filter pressure sits at 8-10 psi. If you’ve observed a significant increase even after you’ve cleaned it (usually pressure gauges have sections which have red markings to indicate if you need to clean it). Then you might need to increase the cleansing frequency.

Another sign to look out for is the water clarity. If you have noticed that your pool is becoming cloudy and there are many particles settled at the bottom of the pool, then there might be a clog in the filters that need cleaning.

Clean Pool Filter - clean your pool filter is an increase in the reading of the pressure gauge that measures filter pressure.

You also might need to clean up after storms. Lastly, it’s also a good idea to clean your pool filters after the chemical treatment of your pools. 

Filter Types And Their Cleaning Procedure

Like what we’ve talked about earlier, cleaning your filter usually means to clean a cartridge filter. So we’re gonna prioritize talking about cartridge filters in this article since we have a separate article about how to clean a pool sand filter and diatomaceous earth filter through backwashing.

Cartridge Filter

This type of pool filter uses a thin filtering membrane or material such as polyester fabric. The membrane is wrapped around the wires of the cartridges which acts as its support when even at high water pressure. [2][3]

Due to this design and build, cartridge filters can’t be backwashed unlike sand filters and DE filters. That is why you’ll need to manually remove and clean the filter cartridges.

Clean Pool Filter - Cartridge Filter

Cleaning Procedure

The procedure below are the common steps from different manufacturers such as Pentair and Hayward.[4][5] So there might be differences when it comes to mechanisms such as locking assemblies, so it’s better to get the specific manual for your cartridge filter and follow the manufacturer’s instructions. 

Step 1: Remove The Air Relief Valve

Before you start disassembling the filter tank, make sure to turn off the pump first. Then you’ll need to relieve the pressure. To do so, you’ll need to open the air relief valve by opening its locking mechanism. It differs per manufacturer so you’ll have to check the owner’s manual on how to open the air relief valve.

To prevent backflow, make sure that you close the suction and discharge lines of the filter tank. Then, remove the drain plug to start draining the system.

Before removing the air relief valve, make sure that the pressure reading on the gauge is zero. Then remove the locking mechanism according to the owner’s manual and remove the relief valve.

Step 2: Remove And Clean The Cartridge Pool Filter And Parts Of The Tank

After removing the air relief valve, remove the top manifold or the enclosure plate on the pool filter cartridge. Then, carefully remove the filter cartridge out of the filter tank.

Depending on the instructions from the owner’s manual, either get a garden to hose or use a pressure washer to clean your cartridge. Start from the top of the filter going down.

If there are debris which can’t be removed by the previous procedure you can soak the cartridge pool filters into either of the solutions below (to make sure of the specific details, kindly refer to the instruction manual of your pool filter cartridge):

  • A pool filter cleaner
  • A triphosphate sodium and water solution
  • Or a detergent and water solution

After soaking, make sure that you rinse and dry the pool cartridge. While waiting, you can take this time to inspect and clean the filter tank and its other parts.

Step 3: Reinstall The Pool Filter Cartridge And The Tank

Once the pool filter cartridge is clean and dry, it’s time to reinstall the filter back into the tank. Place the pool filter cartridge on the bottom manifold (or plate) of the tank and place the top manifold back.

Then reinstall the relief valve on the tank and reinstall the cover of the drain plug. Make sure that it has a good seal. Turn the suction and discharge valve to open. Next is to close the air relief, turn on the pump, and observe the starting pressure. Also, make sure to purge air outside of the system and that there will be no leaks.

Sand Filter

Like the name implies, this type uses sand to trap debris from the steady stream of water coming from your pool.

Clean Pool Filter - Sand Filter

Here are some tips on how to change your pool filter sand for an improved filter.

Backwashing Procedure

Unlike a pool filter cartridge, it can be quite simple to clean a sand filter. The term used for it is backwashing. Backwashing involves reversing the flow of pool water and directing it to the waste pipes.

But like how you clean a pool filter cartridge, make sure that you turn off the pool pump. To backwash the filter sand, simply turn the multiport valve or push pull valve to “backwash” mode. Turn the pump back on and wait as the water starts to clean the sand filter for you.

Diatomaceous Earth Filter

This type of filter system is kind of similar to the sand filter. But instead of sand, it uses diatoms from the earth as its filter media. And like the sand filter, to clean a filter using DE, you’ll only need to backwash with a few added steps.

Clean Pool Filter - Diatomaceous Earth Filter

Backwashing Procedure

Like always, before you clean a pool filter, make sure that you turn the pool pump off. To backwash the filter, set the valve to “backwash” and turn the pump on. Then set the valve to “rinse” and after a while turn it off again. 

Set the valve open to “filter”. To make up for the powder lost during backwashing, add in diatomaceous powder in the filter. Turn the pump on and you’re done.

Other Practices That Help Keep Your Pool Filter Clean

To lessen the time to clean a pool filter, you can implement the tips below.

  • Use a pool cover – Not only is it good in cost saving and retaining the heat of a swimming pool, it is also effective in preventing dust and debris carried by the wind from entering the swimming pool. Discover more how pool covers can help you as pool owners. 
  • Increase the frequency of skimming – The floating particles above the water will eventually be sucked in by the pool filters, so removing it will lessen the burden on the filter.
  • Showering before entering the pool – Showering removes dirt and debris on the human body which lessens the dirt and debris you carry upon entering the pool.

How To Know If Your Pool Filter Needs Replacement

It will come to a point where keeping your filter clean is not enough. Due to natural wear and tear, filter mediums will eventually lose their effectiveness and will need replacement. 

To know the specific service life of your filters, refer to the manual you have. If it is not there, you may have to call in to ask for their help.

Clean Pool Filter - How To Know If Your Pool Filter Needs Replacement

Learn about the importance of maintaining a clean pool filter and its proper cleaning procedures.


Keeping your pool filter clean is essential as it removes dirt, debris, and other possible contaminants. If these particles accumulate, your pool might become cloudy and unhygienic. Accumulation of particles on the filter can also cause the equipment to have low efficiency and breakdowns.

You can change the frequency of when to clean a pool filter depending on your usage, location, environment, and pool filter type. And if you’re experiencing high pressure, unclear waters, and low water flow, you might need to clean 

To clean a pool filter cartridge, you’ll need to manually remove it and clean it. As for a sand filter and DE filter, you’ll only need to backwash it.

Using a pool cover, frequent skimming as part of your pool maintenance, and showering before swimming can help reduce the cleaning load of your pool filter. But if your pool filter is not working properly even after cleaning. Its filtering capabilities might have deteriorated due to continuous usage. So you might need to replace the cartridge filter, sand filter, or whatever the filter medium may be.

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About the author

Brian Anderson

The rather dry pool world out there is in need of some passion to make it shine. With the help of my son Ruben and his wife Maria our mission is to help you create the favorite spot of your house - your pool.

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