Backwashing Pool Filters: Basics and Frequency

There are a few elements of a given swimming pool where cleanliness is important, and one great example here is your pool’s filter. Filters are responsible for removing contaminants from water and keeping the pool healthy, and ensuring their cleanliness periodically is important for helping facilitate these duties.

At Packman’s Pools, we’re here to help clients around Salt Lake City and other parts of Utah with all their swimming pool design and construction needs, plus tips with ongoing maintenance in important areas like these. When it comes to cleaning pool filters, one of the most common processes is known as backwashing. What is backwashing, how often does it need to be done, and how can it be carried out for the three most common types of pool filters it applies to? We’ll answer all these questions across this two-part blog series. 

Backwashing pool filters

What is Pool Filter Backwashing? 

For those just learning about this process, it’s a term used to describe the broad process of cleaning out dirt, debris, chemicals, and other contaminants from your pool filter. This is done by reversing the flow of water through the filter system, which will then push out any matter that has built up within. 

This can be an especially effective option when you’re dealing with chemical imbalances in your pool, but it also serves as a good general maintenance choice to ensure your filter is always running at peak efficiency. The process for doing this will depend on which of three filter options you have in your pool:

  • Sand filters: These are the most commonly found types of filters, utilizing a tank full of sand to catch particles and debris. 
  • Cartridge filters: Cartridge filters are a great choice if you don’t have access to large amounts of land, as they’re smaller in size and take up less room. 
  • DE filters (diatomaceous earth): Another effective filter option, DE filters use diatomaceous earth powder that captures microscopic particles from the water.

How Often Should Backwashing Be Done?

Again, this will depend on the kind of filter you have:

  • Sand filter: These filters typically need backwashing at least once every two weeks, or every ten days if your pool is particularly busy and has a lot of debris.
  • Cartridge filter: Cartridge filters may need to be backwashed more regularly, at least once every week or two, as they can clog up faster than sand filters due to their smaller size.
  • DE filter: DE filters require backwashing whenever pressure reads 8 PSI or more above the normal range – typically once or twice a month.

In part two of our series, we’ll go over some basics on how to backwash each of these pool filter types. At Packman’s Pools, our experienced team of pool engineers and building professionals can provide helpful advice on everything from the ideal filter type for your needs to how to maintain it over time. Contact us today or visit our website for more information!