How to Clean a Pool Filter (DE, Sand and Cartridge)

No matter how often you use your pool, if it is open, eventually the pool filter will need to be cleaned. You will know it's time to clean the filter when the pool water turns cloudy, the filter pressure is elevated from when the pool was opened, or the return water pressure has decreased.

You should clean a pool filter every few weeks or, at a minimum, monthly depending on your exact pool setup and location. Fortunately this is an easy maintenance item for any pool owner to do and generally does not take longer than an hour at most.

Here's how to clean your pool filter, with instructions for cartridge, sand, and DE filters.

What Type of Pool Filter Do You Have?

The first step to cleaning your pool filter is to identify what type you have. This can be done by simply looking at the shape of filter and the type of piping going into your filter. There are three main types of pool filters:

• Cartridge filter: Cartridge filters are usually used on smaller above-ground pools and tend to be on the smaller side. The filter itself is usually secured by a large nut at the top that has to be removed to gain access to the filter inside. The filter will look like a large cylindrical air filter. Most of the time this type of filter does not have a multiport or similar type valve to control water direction.
• Sand filter: A sand filter is the most common type of pool filter. It is usually filled with sand or another filter material. They are potbelly-shaped, and the filter housing is made of plastic. This is controlled by a multiport on top or in front of the filter.
• D.E. filter: DE filters are cylindrical in shape and usually have a stainless steel or metal body. This type of filter has screens inside that catch D.E. powder to enhance the filtering effect. You will have to periodically add D.E. powder via skimmer mouth to maintain efficiency.

How Often Should You Clean Your Pool Filter?

No matter what type of pool filter you have, you should clean or backwash your filter at least once a month. However, some pools may need to be cleaned more often based on what type of filter it has and how many leaves and how much debris falls into the pool.

Being mindful of what the internal filter pressure will help you understand how hard your filter has to work to maintain a clean pool. For example, cartridge filters will have their pressure rise the fastest and should be cleaned every other week because they will lose efficiency permanently if they remain dirty for too long. This is part of the reason they are mostly used for smaller above ground pools and not larger commercial or residential pools. The lower the pressure the system has to operate, the easier it will be for your pool to stay clean, which will help extend the life of your pool system.