A pool filter alongside pipes with words "Types of Pool Filters"

There’s nothing better than diving into a clear, cold swimming pool in the sweltering heat of summer. On the other hand, there’s nothing worse than spending the summer troubleshooting discolored pool water or trying to keep algae from taking over.

Often, the key to a low-maintenance swimming pool lies in your filter. A pool filter that’s too small for your pool or that isn’t cleaned on a regular basis can allow bacteria to build up, leading to green or even brown pool water, scummy buildup, or a foul odor. 

“Shocking” your pool with bleach and chemicals can take care of these problems in the short term, but the overuse of harsh pool chemicals in lieu of a properly working pool filter places additional wear and tear on your liner and other non-metal pool components. Read on to learn about the three main types of pool filters.

Diatomaceous Earth (DE) Filters

These highly efficient pool filters gain their power from diatomaceous earth powder. DE powder is made from diatoms—microscopic aquatic creatures whose skeletons and remains act as tiny sponges. When water flows through DE powder, dirt and debris are trapped in these diatom skeletons and removed from the water. DE filters can catch debris as small as 5-8 microns in size.

DE Filter Flow Rates

Surface Area24 Sq/Ft36 sq/ft48 sq/ft60 sq/ft72 sq/ft
Max Flow Rate48 GPM72 GPM96 GPM120 GPM144 GPM
Safe Flow Rate36 GPM54 GPM72 GPM90 GPM108 GPM

Generally, it is best to keep your DE filter within the safe flow rate zone. However, always ask your local pool specialist for more information about what flow rates to use for your pool.

DE Filter Maintenance

DE filters are fairly low maintenance. You’ll need to backwash them, (rinse away the dirty DE powder), and add new powder on a regular basis. Fortunately, DE pool filters have an easy-to-read pressure gauge that gives you a heads-up whenever a cleaning is needed.

The frequency with which your filter’s DE powder needs replacement depends on how often you use your pool. If you and your family members are in the pool just about every day, you don’t cover the pool at night, or pets use the pool, you may have to clean the filter more often than if you use the pool rarely and keep it covered whenever it’s not in use. As a general rule, you should backwash DE filters every month and perform a thorough cleaning every 4 – 6 months.

Cartridge Filters

These low-cost and low-maintenance filters are often ideal for small above-ground or in-ground pools. Cartridge filters contain anywhere from 1 – 4 cartridges which are made from a tightly-woven material. As water is forcibly pushed through the pleated material of the cartridge, dirt, particles, and bacteria are trapped and removed from the water. These filters are available in a wide range of prices and sizes, so if you’re considering this type of filter, talk with a pool expert to make sure you choose the best one for your specific needs.

Cartridge Filter Flow Rates

Surface Area100 sq/ft200 sq/ft300 sq/ft400 sq/ft500 sq/ft
Max Flow Rate38 GPM75 GPM112 GPM150 GPM150 GPM
Safe Flow Rate30 GPM50 GPM75 GPM100 GPM125 GPM

Cartridge Filter Maintenance

Cleaning a cartridge filter is simple—when the filter pressure rises to a certain point, just pull out the cartridge or cartridges and rinse thoroughly with a hose. You’ll see firsthand all the debris it’s filtered from your pool.

These cartridges should generally be cleaned every 6 months and replaced every few years, depending on use. For a longer-lasting cartridge filter, choose one that is the right size for your pool. Using an undersized filter can increase wear and tear and reduce its lifespan.

Sand Filters

Sand filters are similar to DE filters. However, instead of using diatomaceous earth, they use specially graded silica sand to filter the pool water. All you need to do to keep a sand filter running like new is periodically backwash it and replace the sand every few years.

Sand Filter Flow Rates

Tank Diameter19”21”24”30”36”
Surface Area1.8 sq/ft2.3 sq/ft3.1 sq/ft4.9 sq/ft6.9 sq/ft
Max Flow Rate40 GPM50 GPM60 GPM100 GPM140 GPM

Sand Filter Maintenance

Sand filters require the least amount of maintenance of the three types of pool filters available. Like DE filters, they need to be backwashed occasionally when the filter pressure rises significantly. Sand filters are ideal for landlords, first-time pool owners, those who are often away from home during the summer, or anyone who would rather spend more time in their pool than cleaning the filter.

Need a New Pool Filter or Pool Maintenance?

Regardless of which type of filter appeals to you, Liquidus Pools Services is your go-to place for questions, filter purchases, and service needs. Our experienced team members will provide all the product information you need to make an informed purchase. We can also clean your pool filters if you don’t have time to take care of these cleanings yourself. And if you ever run into pool filter issues, we are just a phone call away! Contact us today for more information on our services or to schedule an appointment.

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