How to Clean Your Pool’s Filter

person pulling out pool filter

No one wants a dirty pool. But all the work you do fishing out leaves will be for nothing if you don't also learn to clean your pool's filter.

There are a few different types of pool filters, each with a different cleaning process. This article will offer some advice on cleaning each one and making sure your pool runs smoothly for years to come, giving your friends and family lots of enjoyment and a safe way to beat the heat on hot summer days.

Why You Should Clean It

A pool filter keeps your pool clean and safe for swimmers. With proper care, a filter can last 5-10 years.

Pool filters can be expensive, though, ranging in price from a few hundred to a few thousand dollars, depending on the size of your pool and the type of filter you choose to use.

As a result, cleaning your filter and making sure it's in good shape should be a priority to extend its life and save your pocketbook an added expense.

Is It a Project I Can DIY?

Cleaning a pool filter is absolutely a project you can do yourself by following a few basic instructions. This will save you a lot of money compared with calling in a professional anytime you need your pool cleaned.

Make sure you understand what type of filter you have and read the manufacturer's instructions before you begin. Don't do anything that goes against the instructions in a way that could void your warranty or harm your filter.

Hard vs. Soft Water

People often think about hard and soft water in the context of showers and sinks, but you should consider them when thinking about the water in your pool as well.

With a pool, you need some hardness because of the chemicals necessary to keep your pool healthy. This also can lead to pool filters needing to be cleaned more regularly to deal with hard calcium and other chemical build-ups.

Types of Filters

pool filter getting cleaned with water

There are three types of filters you're most likely to find in pools, each with its own, unique cleaning method. Before you begin to clean your filter, make sure you understand what type of filter you're dealing with.

Cartridge filters are one of the most common types of pool filters. These filters are efficient to maintain. Unlike some other filter types, they don't require a ton of water during the cleaning process, making them a great option if you're in a drought. These filters push water through their filter, which is made of fabric. The fabric holds onto the particles, pushing out only the water.

Another common filter type is diatomaceous earth, or DE, filters. These filters are known for their high levels of efficiency, and also their high price tags. In a DE filter, pool water is pumped through the filter, which filters out unwanted particles and pumps out the clean water. It can be a pain to clean DE filters because a few different items will need to be cleaned.

The third type of pool filter is a sand filter. Sand filters are generally the most affordable filter option on the market, but they aren't as effective as the other filter options. These filters work by pumping water through a silica sand-filled tank, which holds on to debris and pumps out clean water.

Cartridge Filters

As previously mentioned, cartridge filters are common. Over time, they'll collect the particles they filter out of your pool, necessitating a filter cleaning. Read the manufacturer's directions to find out how often you'll need to do this. They should include information on what number the filter gauge will display when it needs to be cleaned.

Once you determine it's time to clean your filter, start by turning off the system. Keep people away from your pool while you're cleaning the filter.

Once you turn the system off, you'll need to bleed the filter. To do so, turn the relief valve into the open position. Then open the filter tank by removing whatever is being used to secure the lid on top of the tank. In many cases, this will be an o-ring that can be removed relatively easily. Your owner's manual should tell you how to open the filter tank.

After you open the tank, remove the cartridge from the tank. In most cases, the filter will be easy to lift right out of the tank. If the filter, or in some cases filters, are being held in place, remove the clamps according to the manufacturer's instructions before lifting the filters out of the tank.

Once the cartridge filter is out, check it to make sure it's not frayed or ripped. If it's torn, you'll need to replace the filter instead of just cleaning it.

Use clean water to clean the filter. A garden hose with a nozzle attachment is an excellent option. Start at the top and work your way down.

Repeat this process a few times, changing the angle of the filter each time to ensure a great clean. You might consider using a commercial pool degreaser to get an even deeper clean.

Once it's cleaned, put the cartridges away the same way you took them out of the filter tank. Put the lid back on and make sure the clamping mechanism has been secured. You can now turn the air release back to the closed position and turn on the system.

two pool filters, one dirty one clean

Other Methods

If the hose is not enough to get the debris out of your filter, there are a few other methods you can try. The first is to try using an air compressor. Some people choose to use an air compressor first to save water.

You can also use dishwasher detergent to clean the filter cartridge. To do this, mix one cup of detergent in five gallons of water and soak the filter for at least five hours. Rinse the cartridge until the water used to rinse it runs dry and reassemble the filter.

Vinegar is another great option for cleaning the cartridge. Combine water and vinegar in a large bucket and let the cartridge sit there for at least three hours. Make sure to flip the cartridge over a few times. After the soak, rinse the cartridge thoroughly and put it back in the filter.

You can also make your own cartridge filter cleaner with a cup of Trisodium Phosphate in five gallons of water.

Diatomaceous Earth Pool Filter

DE filters will also need to be cleaned eventually. This process is actually fairly easy and something anyone should be able to handle. Start by flipping the filter to the backwash position. This switch should be easy to find on the filter.
Once you have switched it to the backwash position, it is time to open the run-off valve. You now will need to turn off the pool filter. This will allow the dirty water and DE to flow off the filter.

Next, close the run-off valve and switch the control away from backwash and back to filter mode.

You can add more DE through the pool skimmer. Make sure you read the manufacturer's instructions on your particular filter to know how much DE to add. This can vary widely, so don't skip this step. Make sure you also read the manufacturer's instructions on when to clean the filter.

Sand Filter

sand filter for pool

To clean a sand filter, start by stopping the filter pump. This ensures nothing will happen while you're cleaning the device. Once the filter is off, close the valves on both the suction and return lines to which the pump is attached.

Once everything has been turned off or closed, open the cover of the pump. Once it's opened, you'll be able to remove the basket containing the filter, which you will then be able to empty.

Now open the valve and turn the lever to the backwash position. Let this run for as long as the manufacturer suggests in your user's manual. While the device is backwashing, slowly add sand filter cleaner to ensure a thorough cleaning. The sand in your pool filter should be replaced roughly every three to five years.

Next, reopen the valves to the suction and return lines and start the pump.

After it's run for about five minutes, stop the pump. You'll now need to turn the lever to the rinse position for roughly one minute.

After you've rinsed the filter, move the lever to the filter position. This is the position the lever should have been in before you started to clean the device and is the position the device should be in on a daily basis. You can now start the pump back up.

    Other Maintenance

    Cleaning out your filter is an important part of pool maintenance. Ideally, you'll be running the filter at all times but for a minimum of 10 hours a day to ensure it is doing its job.

    The filter's hard work won't be enough, though, if you don't take other important steps to maintain your pool.

    To start, you'll need to keep the water clean. Your filter will do a lot of this for you but you should fish out bigger items like leaves and branches yourself. Consider doing this once a week to prevent a build-up of larger items. If your pool has a cover, you should use it often to prevent things from getting into your pool.

    Make sure the pool's interiors are in good condition as well. This means checking to make sure the tile and concrete in your pool aren't cracked or damaged.

    To ensure the pool is safe, pay special attention to the chemistry of the water. To do so, start by using a water testing kit on the water. This will tell you the makeup of your water so you can better understand what needs to be added to strike the right balance.