There are three basic types of pool filters used to clean the impurities from the water in swimming pools. The different types are sand filters, cartridge filters and diatomaceous earth (DE) filters. Any of these filters can be used to maintain any pool.
The most inexpensive of the three kinds of pool filters are the sand filters. This type of filter works by filtering water through a bed of sand. Lateral tubes at the bottom of the sand then separate the clean water from the dirty water. Water is pushed through the filter sand, and as the filter separates the water, the dirty water is sent to the top while the clean water exits through the bottom.
Debris can plug up and block sand filters, causing the pressure to increase in the filter, dropping the flow of water. This can be fixed by running the system in reverse to backwash the filter, leaving it cleaned. The filter is then placed on its rinse mode where it repacks the sand back into the filter.
Maintenance can be done manually every couple of weeks to keep the sand filter in proper working order. Sand filters are inexpensive and easy to replace. The downside to owning a sand filter is that it sometimes allows smaller particles to pass through into the pool.
Cartridge filters are considered to be the most economically low in maintenance. Water runs through a filter inside this particular system, catching any debris. It is very similar to water filtering systems that are used in homes.
These type of pool filters do not clog up as much as the other pool filters, and two types of filter elements can be used in the cartridge filter system. The less expensive elements may be cheaper to replace, but they also need replaced more frequently. The more expensive elements tend to last longer.
Cartridge filters are created to run on lower pressure. They filter out more particles than sand but not as many as DE filters. These filters can be cleaned once or twice during the swimming season by simply hosing them off with water.
DE filters use diatomaceous earth to filter particles out of the water. They are composed of plastic grids inside of a plastic type of fabric. DE powder coats the grids and filters out tiny debris. If the pressure rises in the filter, the system automatically backwashes, similar to the sand filter, recharging itself with more DE powder. DE filters can cause some inefficiency and water flow loss because they tend to run at a higher pressure than cartridge filters.
