You may know that the pool filter is one of the most important pieces of equipment in your swimming pool.  In order to keep your water sparkling clean, you need to perform regular maintenance on your pool filter. Whether your pool uses a sand, cartridge, or diatomaceous earth filter, there is a general rule of thumb that can be used to determine when it’s time to clean your pool filter: Take a reading when the filter is clean, and when the pressure rises by about 10psi, you’ll know it’s time to clean the filter again.

Here are a few tips on how to clean each type of pool filter.

Sand Filter

It’s important to backwash your sand filter anywhere from every few days to once a week, depending on how much you use your pool. Begin by cleaning out your pool skimmers, turning off the pump, and emptying the pump basket. Turning off the pump before turning the backwash valve is an essential step, because failure to do so can cause serious damage to your equipment. Turn the backwash valve to “backwash”, and then turn on the pump. Most filters have a view glass, which allows you to see the debris coming out of the filter. Let the pump run until the water in this view glass appears clear. Turn the pump off again and turn the backwash valve to the “rinse” or “filter” setting, depending on the type of filter. Let it run for about 15 seconds, and then repeat the backwash cycle. Finally, turn the pump off and turn the backwash valve back to the “filter” position, before turning the pump on again. New filter sand is very rough, which makes it effective in filtering dirt particles out of your pool water. Over time, the sand is smoothed and worn down, decreasing your filter’s efficiency, which means your filtration system has to run more frequently in order to keep your pool water clean. For this reason, it’s a good idea to change the sand in your filter every 5 years. Unless you have a basic knowledge of plumbing, changing your filter’s sand is a task that is best left to a professional.

Cartridge Filters

Cartridge filter maintenance is relatively simple. Like with sand filters, it’s important to turn off the pump before beginning. You just need to gently rinse the loose debris off the cartridge, and then soak the cartridge overnight in an alkaline based cartridge cleaner solution. Lastly, rinse the cartridge again to wash off the chemicals and any lingering debris. Remember to never to spray the cartridge with too much water pressure, because this can push dirt into the membrane.  Over the long-term, it’s a good idea to change your cartridge every 3-5 years in order to keep your pool water as clean as possible.

Diatomaceous Earth Filters

Diatomaceous earth (DE) filters should be cleaned about once every month. Cleaning your DE Filter consists of three basic steps: Backwashing the filter, cleaning the grids, and finally, adding new DE. If your DE filter has a push/pull or multiport valve, you can backwash the filter using the same steps described above for sand filters. With sand filters, the sand is not removed when backwashing, however, with DE filters, the DE is removed along with the dirt, and so fresh DE has to be added afterwards. Again, the most important part is to always ensure the filter pump is off before changing the valve position. After backwashing, “recharge” or “recoat” the pool filter grids with fresh DE filter powder. To do this, run the filter pump and slowly add 1 pound of DE for every 10-12 square feet of filter space. It’s best to check your owner’s manual for exact specifications, because not adding enough DE in the filter can cause equipment damage or inhibit filtration. Once or twice a year, it’s also a good idea to remove the DE filter grids and wash them. The exact way to clean your specific DE filter is typically described in the manufacturer’s instructions. As with all swimming pool maintenance, if you feel uncertain about how to perform the steps correctly, it’s best to contact a swimming pool technician. Time for a new pool filter?  Shop online and get free shipping across Canada on thousands of products.