How to Clean a Pool Filter

To enjoy your backyard swimming pool as much as possible, it’s essential to regularly clean and maintain the filtration system. In this article, you’ll learn how to clean a pool filter and other useful pool maintenance tips.

Whether it’s an in-ground or above-ground swimming pool, your pool maintenance routine gets much easier when you know how to correctly care for the type of filtration system you have.

To keep your pool water looking clean and clear, cleaning pool filters before they clog or become too dirty is critical. As your pool pump circulates water through the filtration system, particles of dirt and debris get trapped in the filter.

Microscopic contaminants like algae, bacteria, body oils, and sunscreen also get filtered out. As such, it’s necessary to regularly clear the filter of all of the debris it’s collected to keep water flow levels steady and prevent it from becoming clogged.

Best Ways of Cleaning Pool Filters

Part of in-ground and above ground pool maintenance is keeping the filter clean. This is a task made easier if you have pool friendly plants and trees as part of your landscaping.

The best way to clean your pool filter depends on several factors: what type of filter you have, how often you use your swimming pool, what your climate is like, and whether or not you have hard water.

Always be sure to thoroughly read the cleaning instructions for your specific pool filter before performing any maintenance procedures to avoid accidental damage.

There are three principal styles of pool filters: cartridge filters, sand filters, and diatomaceous earth, or DE filters. Each kind of filtration system has unique advantages and different maintenance protocols.

Read on to learn all about how to clean a pool filter cartridge, backwash a sand or DE filter, and extend the working life of your pool filter.

If you are trying to clean a green pool, filter cleaning is an important part of the process.

How to Clean Pool Filter Cartridge

Cartridge filters, like Hayward, are the most widely used type of pool filter because they’re efficient and straightforward to maintain. They’re also more eco-friendly because they require less water use during the cleaning process.

A cartridge filter works by pumping the pool water through a cylindrical filter cartridge made of pleated polyester fabric. The fabric traps particles in the water and catches smaller particles than other pool filters.

When it comes to how to clean pool filter cartridge fabric, there are various approaches. Choosing one depends on how dirty the filter is and the supplies you have available.

Turn off the pool pump at the breaker, then drain the air from the system using the pump’s air relief valve, normally at the top of the filter.

Remove the top of the filter. Consult your owner’s manual to ensure that you don’t accidentally damage the filter housing.

After removing the pool filter cartridge, closely inspect it for any signs of cracking, tears, or other damage. If the filter is damaged, it needs replacing.

Check the o-ring on the filter tank, too. Replace it if you notice any cracks, dry rot, or warping. Otherwise, apply a non-petroleum-based lubricant to keep it from drying out before your next cleaning.

Cleaning a Pool Pump Filter with a Garden Hose

The first step to clean and clear a cartridge filter is rinsing the cartridge to remove buildup.

Using your garden hose spray nozzle at an angle works best to reach between the filter fabric’s pleats. Avoid using a pressure washer, as that’s likely to harm the cartridge.

How to Clean a Pool Filter with Dishwasher Detergent

It’s possible to use dishwasher detergent to clean your pool filter cartridge. Mix one cup of detergent per five gallons of water and soak the filter for three to ten hours.

Use the spray nozzle attachment on your garden hose to rinse the cartridge until the water runs clear before reassembling your pool filter.

Clean Pool Filter Cartridge with Vinegar

If your pool filter is grimy, soak the cartridge in a cleaning solution of vinegar and water for a few hours. The acidic nature of vinegar is ideal for getting rid of algae in a swimming pool as well as bacteria and breaks down calcium deposits.

Vinegar is safer and more environmentally friendly than muriatic acid, which causes serious chemical burns and lung damage if it comes in contact with your skin and eyes or if you inhale the fumes.

White distilled vinegar is also significantly less expensive than other pool filter cleaning products.

After rinsing it, submerge the filter cartridge in a large bucket and fill it with a cleaning solution of equal parts water and distilled white vinegar. Soak the filter for three to ten hours.

About halfway through the soaking time, turn over the filter in the bucket to ensure that all the filter parts get exposed to the vinegar solution. Once it’s done soaking, rinse the filter again before reinstallation.

Homemade Pool Cartridge Filter Cleaner

Sunscreen and body oils are challenging to remove from your pool filter cartridge. However, using a stiff-bristled brush on your cartridge filter to remove contaminants may damage the polyester or paper pleats.

To remove stubborn residue, be sure to use a soft-bristled brush designed explicitly for cleaning cartridge filters to avoid accidentally ruining the cartridge.

Instead of purchasing expensive chemicals, try making your own DIY filter cleaning solution.

In a five-gallon bucket, blend the ingredients and submerge your filter cartridge in the cleaning solution. Soak for three to ten hours. After soaking, rinse the cartridge before reassembling the filtration system.

Always check your filter’s maintenance manual and warranty information before using DIY cleaning products to ensure that you won’t damage the product or void the warranty.

Cleaning a Sand Filter

Sand filters are the most affordable pool filters. The pool water pumps through a filter tank filled with silica sand, which traps contaminants and debris before pumping clean water back into your swimming pool.

While they’re economical, easy to maintain, and long-lasting, they aren’t as effective at trapping the smallest particles in the water.

The average sand filter has a micron filtration rating of 20-40 ppm, while cartridge filters typically have a micron filtration rating between 5-20 ppm.

Always refer to the specific maintenance manual for your pool filter when cleaning it to avoid accidental damage.

Backwashing a Sand Filter

To determine when to clean your sand filter, pay attention to the system’s pressure gauge. Most filtration systems run between 5-20 psi. Check the owner’s manual for any specific recommendations for your system.

Backwash the sand filter when the filter pressure gauge reads eight to ten psi above the average level. Turn off your pool pump, then move the filter valve to the ‘backwash’ position.

Turn the pump back on and backwash the system for at least two minutes or until the water in the filter’s sight window is clear. While backwashing, slowly add sand filter cleaner to the skimmer.

Once the initial backwashing is complete, turn off the pump and switch the filter valve to the ‘rinse’ setting.

Turn the pump back on and rinse the filter for at least one minute. Finally, turn the pump off and move the filter valve back to the ‘filter’ position, and turn the pump on again.

When to Replace the Sand in your Pool Filter

In general, the sand in your pool filter should be replaced every three to five years. However, the working life of silica filter sand depends on how often you use the pool, oil and grease levels in the water, and if you have hard water.

If you notice your filter running slowly or inefficiently, or the backwash cycles are shorter than normal, chances are your filter sand is dirty and clogged.

With excess oil and grease buildup, the sand sticks together, and water cannot pass through as intended. Instead, it creates a channel along the side of the clumped sand and gets pumped back into the pool without filtration.

Maintenance for a Diatomaceous Earth Pool Filter

Diatomaceous earth, or DE filters, are the most effective pool filters, albeit the most expensive. A DE filter works similarly to a sand filter.

The pool water gets pumped through a fine white powder made up of fossils of single-celled aquatic plants called diatoms. DE powder filters out the smallest particles in the water, down to four microns.

Also, DE filters are more energy-efficient, using less power pumping pool water through the fine DE powder compared to other filters. Like a sand filter, DE filters get backwashed. However, a few extra pieces of a DE filtration system also require cleaning.

Clean your DE pool filter whenever the pressure gauge reads eight to ten psi above the average level. Always read the specific maintenance recommendations for your pool filter in the owner’s manual to prevent accidental damage.

How to Backwash a DE Filter

The first step in cleaning your DE filter is to perform a backwashing cycle to clear out excess debris. Turn off your pool pump, then switch the filter valve to the ‘backwash’ setting.

Restart your pool pump and run the backwash cycle until the water coming out of the discharge hose runs clear. Turn off the pump again and return the filter valve to its normal position.

Open the air relief valve and remove the drain plug to empty the filter tank. Once it’s drained, open the filter tank according to your owner’s manual instructions and remove the manifold.

Take out the grids and rinse them with your garden hose. Rinse the inside of the filter tank with the garden hose, as well.

Replace the filter tank lid after lubricating the o-ring or gasket and release the excess air through the air relief valve. Turn on your pool pump, and close the air relief valve once water begins flowing out. The pool pump must be running before adding DE powder.

Check your owner’s manual for the exact amount of DE powder to add. Combine the DE powder with enough water to form a thin, creamy paste.

With the pump running, pour the DE mixture into the pool skimmer. The filter draws it in and distributes it over the filter grids. Run the pool pump for at least a half-hour before turning it off.

Safely Disposing of Used DE Powder

Some cities have bans against disposing of DE waste in the public sanitary sewer system. To verify regulations in your area, contact your local water department.

Food grade diatomaceous earth and DE powder meant for pool filtration are prepared and treated differently. Pool grade DE is heat-treated to turn the silicone dioxide into crystalline silica.

Food grade DE contains less than one percent crystalline silica, while pool grade DE contains 60-70%.

Crystalline silica is severely harmful when ingested into the lungs. It’s linked to numerous lung diseases and respiratory complications. Therefore, always use protective equipment when handling DE powder.

Dispose of DE waste in a sealed plastic bag in the garbage. Use a plastic bucket with tiny drain holes punched in the bottom, lined with several inches of dirt, to catch the DE waste as you backwash your pool filter.

Maintaining a clean filter is a critical part of regular pool maintenance. Always consult your owner’s manual to determine the specific requirements for how to clean pool filter cartridge pleats or backwash a sand or DE filter.

While cleaning your pool filter system, it’s a good idea to check the hosing and other components for signs of wear and tear and replace parts as needed.

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