Swimming pool filters

A swimming pool filter is an essential piece of swimming pool equipment and without it a swimming pool would quickly become dirty, unhygienic and potentially dangerous.

A swimming pool filter does exactly what its name suggests, it filters dirt, external debris and other alien matter out of the water and then sends the clean water back into the swimming pool.

There are many different types of swimming pool filters, but the two basic types are sand filters and cartridge filters.

Sand filters

A sand filter uses a very simple tried and tested approach. The filter takes the form of a cylindrical vessel that is filled with a special filtration sand. This filtration process works by sending pressurized water from the swimming pool through the sand, thereby allowing the sand to capture any particles or debris that are in the water. Clean water is then ejected from the bottom of the filter.

Naturally, the deposits in sand filters need to be removed and this is done very simply by reversing the direction of a two way valve that forces pressurized water up (rather than down) through the filter. This waste water is then directed to a drain zone. This process in known as back flushing.

Sand filters can be quite large and their use is nearly always restricted to in-ground swimming pools or the larger above ground pools.

Cartridge filters

Cartridge filters use the same filtering process as sand filters, the difference being that the filter has a removable cartridge that is either emptied and cleaned, or replaced. These filters use paper as the filtration media and they are very effective and easy to maintain. They are very similar in appearance to the air filter on a motor car.

The cartridges in cartridge filters only have a limited life and, although they can be cleaned and re-used a few times (by washing or hosing with water), they require frequent replacement.

Cartridge filters tend to be used primarily on small to medium sized above-ground pools. Some of the smaller and more portable cartridge filters can be clipped or hung over the side of above-ground pools and removed when not in use.

Pumps

For a filter to work it requires a pump. Pumps can be bought separately, or as part of a complete ready to use kit including the filter.

A key consideration to take account of when buying a swimming pool pump is the running noise. If the pump is housed in a utility building, or below ground, then this is not an issue, but pump noise can be disruptive if it is located close to the pool or patio area without any sound proofing.