Why Cartridge Filters?
Cartridge Pool Filters are simple to use and powerful equipment to filter and circulate water in swimming pools. Cartridge Filters use a synthetic polyester as the filter medium, compared to Sand or Diatomaceous Earth like other pool filter options. Though they can’t filter has finely as D.E. filters, Cartridge Filters can filter dirt and debris between 5-20 microns.
Simple Maintenance
Cartridge Filters do not require backwashing. In fact, they don’t even have a backwash valve. This not only makes the hydraulics in the system fairly simple, but cleaning is also a breeze. The cartridge element (filter cartridge) can be removed and pressure washed for easy maintenance. All you need to do is remove the cartridge element, soak them in a filter cleaner and then put them back in the filter tank. Once the filter element is beyond repair, just swap it out with a replacement filter cartridge and you’ll be good to go!
Watch The Filter Pressure Gauge
Keep an eye on the pressure gauge. When you replace a filter element, take note of the start-up pressure (PSI). Be sure to mark this spot on the pressure gauge with a grease pencil. Then, recommend mentally adding about 10 PSI to that reading and add another mark the pressure gauge with a grease pencil. The area in between is your normal operating pressure. When the pressure gauge hits the higher mark, it’s time to clean the cartridge element. You should only need to do this about twice per year with newer cartridge filter models. NOTE: if the filter goes too long before cleaning, the filter cartridge element may get damaged.
A Little Dirt Don’t Hurt
Similar to a sand filter, cartridge filters actually perform better with some dirt on the cartridge element. This is because the dirt creates a tighter web in the filter material, capturing smaller particles than it would if clean. This doesn’t mean that you can skip cleaning or replacing the cartridge element – it just means that a slightly dirty element can capture more dirt than a brand new element.
Pool Service professional may opt to just replace the filter cartridge each time with commercial swimming pools. Or they may rotate between to filter elements – replace one, and take the other for cleaning. It’s up to the professional for this option.
source: https://blog.poolsupplyworld.com/pool-cartridge-filter-care/