For pool owners, few things are as satisfying as crystal clear water on a summer day. To ensure that clarity remains all season long, it’s important to properly maintain and clean your pool’s filter.

Effective filter maintenance is important throughout the entire pool season, but it’s especially critical to make sure your filter is working properly as peak season approaches. Whether you have a sand, cartridge or DE filter, there are important maintenance procedures you should follow and key products you can incorporate into your filter-maintenance program.

“The most important thing is to know what the pressure is in your filter when it is clean,” says Rick January, technical services representative with Arch Chemicals, Inc., now part of Lonza. “This provides a base to tell you when it is time to maintain the filter. Once the filter pressure increases by 8 to 10 psi above the level when the filter is clean, it is time to backwash a sand or DE filter, or remove and clean or replace a cartridge filter.”

Sand filters: What You Need to Know

Knowing when to change the sand in your filter probably won’t be obvious. But if you’re

keeping up on regular maintenance and don’t have an issue such as algae in your pool—and your water still is not as clean and clear as you expect—it might be time to change the sand, January says.

If you’re like most pool owners with a sand filter, you’re changing the sand about every three to five years, depending on use. Because changing the sand is not part of your

daily and monthly maintenance routine, it’s important to follow directions and—if you’re not comfortable going it alone—call your local dealer for assistance, January says.

It’s critical to use sand that is “pool filter” grade, not the stuff your kids have in their sand box, January says. Once you have the proper sand on hand, be cautious when replacing and adding it to your filter.

“Removing the old sand must be done carefully so as not to damage the filter laterals and other components,” January says. It’s also important to use the proper amount of sand based on recommendations from your filter manufacturer. Using too much sand or too little affects filter efficiency and can cause water balance and clarity issues.

To change the sand, unbolt the filter’s tank or remove the valve at the top of the device, says Bob Matey, president of Aquadoc Pools in North Huntingdon, Pa. “Just take

the valve off the top and dump [the old sand] in a garden or sprinkle it lightly through

the yard,” he says.

Consider these other tips for sand-filter maintenance:

  1. The inside of your sand-filter tank has a pipe connected to the plumbing system. Make sure not to dump sand into the pipe, Matey says. “Pour around the pipe or you’ll clog it up,” he says. “If there’s no lid on the pipe, place a cup over the pipe opening while you pour in the new sand.”
  2. It takes about six days for sand filters to get dirty, Matey says. “Check the gauge to determine when the sand is dirty,” he says. “Every pool is different, so it’s hard to know if you will need to backwash once a week or more or less.”

In addition to backwashing your sand filter, consider cleaning it with chemicals twice per season—either at the start of the season and in the middle or during mid-season and when closing the pool.

Cleaning your cartridge filter

Determining how often to clean your cartridge filter depends on the filter size. Use the filter gauge to accurately determine when cleaning is required. To clean your cartridge filter, turn off your pump, remove the filter head, lift out the filter and clean it using a filter cleaner.

Unlike maintaining sand and DE filters, you cannot backwash cartridge filters, January says. One of the advantages of removing and cleaning the cartridge is you can inspect it more regularly to ensure it’s in good operating condition. If you’re using filter cleaners to clean your cartridge filter, make sure to follow the instructions on the labels, as they

must be used in the proper order.

DE filter maintenance and replacement

When it comes to DE filters, backwashing is part of the standard maintenance routine. After you backwash the filter, you must add new DE media through the skimmer to recoat the filter grids, January says. When disposing of the spent DE media, it’s important to look to manufacturer recommendations, as well as local regulations, for guidance.

You should change the DE media each time you backwash the filter, and it’s a good idea to clean and inspect the filter housing and grids once a season, or as recommended by the manufacturer, January says.

DE filters have finer filtration than any other filter type, as they clean particles down to five microns in size, Matey says. To ensure effective filtration, change the DE filter when it gets dirty or when the pressure gauge increases 8

to 10 psi above the clean-filter pressure.

It’s important that filters are always top of mind when compiling your pool maintenance program. Following these procedures will help ensure you have sparkling blue water all season long.

“Pay attention to your filter,” January says. “Listen for odd sounds and note any leaks, pressure variations or other physical indications of problems. If something is not

right, don’t neglect it.”

Effective Pool Products to Clean Your Filter

Regardless of the type of filter you have for your pool, there are important products you should have on hand as part of your maintenance program.

If you have a chlorine pool, consider these products from the POOLIFE® brand:

  • POOLIFE® Backwash Filter Cleaner is a sand-filter product you should use each time you backwash the filter. It’s a fast-acting product that removes oils, grease and fine particles that stick in the filter.
  • POOLIFE® Filter Cleaner removes oil, grease, dirt, and soap from all filter types. The cleaner is composed of an acidic solution that breaks down organic and inorganic matter that accumulates in filters.

If you have a chlorine-free pool, consider these

products from the BAQUACIL® brand:

  • BAQUACIL® Universal Filter Cleaner dissolves and removes collected debris, scale, rust and organic waste from sand filters and cleans and unclogs DE filter grids and cartridge-filter elements.
  • The BAQUACIL® Backwash Filter Cleaner is a fast-acting product for sand filters that removes organic and inorganic buildup, as well as cleans the sand particles as you backwash.