A pool filter is used together with a pump to push water through the filter system. The pump directs water from the pool skimmers to the filter media, which traps microns—dirt, dust, hair, oils, and other tiny particles—and lets clean water back into the pool.
Choosing the right filter ensures good water flow/circulation, keeping your pool free of debris and contaminants. There are three different types of pool filters, all of which help to keep the water clean. But each type of filter is suitable for specific applications, which in turn affects its effectiveness and lifespan.
The three types of pool filters in the market are sand filters, cartridge filters, and diatomaceous earth (DE) filters.
Sand pool filters have the simplest design compared to the other two types of filters. They are made up of sand, which filters the dirty water as it is pumped through the system. As microns accumulate, water flow through the unit diminishes. You need to activate the backwash valve to push out old the sand and micron mixture (reset the filter). You should also replace the sand or sand mixture in the filter every 3-5 years, though it can last for up to 7 years. Clean sand with cleaner after each season.
DE filters are comprised of a tank with 8 fabric grids with DE coating. This coating is actually a powder obtained from fossilised diatoms that attract particles and help trap contaminants as small as 3 microns. Sand filters can only trap contaminants as small as 20 microns. As such, DE filters offer the best filtering capability. These filters also rely on bumping to loosen dirt around the grid and keep the filter functional for 7 to 10 years, at which point the filter grids need replacing.
Cartridge filters use a set of 4 cylindrical fiber cartridges to trap contaminants as small as 10 microns. They don’t contain a backwash valve, so they use the least amount of water. To clean them, you simply remove the cartridges, rinse them down, and then replace them. Use a cartridge cleaner when pleats are dirty. You can do this for 3-5 years before replacing the cartridges.
Your choice of pool filter may depend on the desired level of water clarity, longevity, maintenance requirements, water usage, and cost of replacing the set. Cartridge filters are the most economical, DE filters offer exceptional filtering capability, and sand filters are low-maintenance.
All types of filters will make pool water safe and reduce the risk of injury from physical contaminants and waterborne illnesses. But you should also ensure that you get the right size filter for your pool size and level of activity.