Types of Swimming Pool Filters

There is nothing more relaxing in the summer than a cool dip in a swimming pool. However, for this fun to be undiluted, the water should be clear of dirt and any type of debris. This is where the swimming pool filters come to the rescue. These devices work round-the-clock to filter out the minutest impurity so that one can enjoy swimming or even just relaxing in the pool.

Types of Swimming Pool Filters

Sand Filters

As the name suggests, sand is the filtering medium in these filters. The pool water enters from the top and is pushed down through beds of sand inside the filtering tank. The sharp edges of the sand particles hold the impurities back, and pure water flows out from the bottom. However, as this process continues, more and more dirt accumulates in the filter. As a result, pressure increases on the filter and the flow of water reduces. When this happens, the filter needs to be cleaned through a process known as 'backwashing'. In this process, water enters the filter from the bottom and exits from the top. This washes away the debris collected between the sand particles. The dirty water is removed from a separate waste line. This process should be repeated once every few weeks. In case the sand in the filter gets really dirty it can be easily replaced. The disadvantage of using a sand filter to clean pool water is that a lot of water from the swimming pool is lost and this water must be replaced. Moreover, this filter is not very efficient in removing debris from water as sand removes particles that are only 20 to 25 microns in size. Particles smaller than these are allowed to re-enter the water in the pool.

Cartridge Filters

A cartridge filter has filtering elements in the shape of cylinders. These cylinders are made of polyester, or any other material that acts as excellent filtering surface. As water passes through these filters, impurities are caught and retained in them until they are cleaned. Cleaning these filters is very easy. They may simply be washed with water from a hose pipe. Some families even soak them in a detergent solution for sometime and then put them back in the pool. Although these are more expensive than sand filters, cartridge filters are becoming increasingly popular due to the low maintenance required, and also because they can filter impurities as small as 5 to 10 microns in size.

Diatomaceous Earth Filters

These filters are the most efficient as well as the most expensive. The filtering material used is diatomaceous earth, which is the fossilized exoskeleton of minute diatoms. The diatomaceous earth is used to coat the grids in the filtering tank. As water passes through the tank, the diatomaceous earth act as sieves that hold back impurities as small as 5 microns. These filters are cleaned by the process of backwashing in which the water flows in a reverse direction and removes the dirt accumulated in the filter. The dirty water is then drained out of the system. After the filter is thus cleaned it could be 'recharged' with some fresh diatomaceous earth. These filters however run at higher pressure than cartridge filters and hence can cause flow loss and extra pressure on the pump.

While diatomaceous filters give cleanest water, cartridge filters are low maintenance and do the filtering job well enough. Also diatomaceous earth can be added to make sand filters more effective. Which is the best filter for one, is a matter of one's requirements and the effort one is ready to put in to clean and modify a filter to increase its efficiency.