Cartridge pool filters are the easiest to maintain and the least expensive to purchase. They work well with small above ground pools. They work by trapping dirt particles in the cartridge and passing the clean water back into the pool.

When the cartridge gets too dirty, open the filter, pull out the cartridge, spray it with a garden hose to wash it off and pop it back in. The cartridge does need to be replaced about once a year. Depending on your filter a replacement cartridge can range from $40 to $100.

Sand filters, which are a bit more expensive than cartridge filters, work by passing the dirty pool water through a sand filtration system. The dirt particles are caught in the sand and the clean water is sent back to the pool. They are usually more expensive than cartridge filters, but also just as easy to maintain.

When the sand gets dirty you must perform a backwash, running the filter in reverse to remove the excess dirt (there is a backwash spigot so the dirty water doesn’t return the pool). Unlike a cartridge, you can use the same sand for approximately five years.

These are usually a bit more expensive than either of the other two filters. They work by coating the filtering mechanism with fine diatomaceous earth (DE). The DE coats the internal filter system and removes the tiniest of dirt particles. Known for their ability to screen out particles as small as three microns, DE filters are popular for those who want the cleanest pool water.

Cleaning a DE filter includes backwashing and/or manual cleaning. You must add more DE to the system each time it’s cleaned. At approximately $20 for 15 pounds of DE (which is more than enough to last a full season or more), it is much less expensive to maintain than a cartridge filter.

The pool pump pulls the water from the pool into the filter. The pump consists of the pump basket (which collects debris and leaves), the impeller (a fan-like mechanism) and the water discharge. The discharge is the connection point that pushes the water from the pump into filter’s housing.

Just as important as the pump is the motor. The motor gets everything moving. Without the motor, the water could not leave the pool to enter the pump. The motor initiates the movement necessary to create the vacuum to pull the water from the pool into the pump.