There are 3 types of filters – Cartridge Filters, Sand Filters and Diatomaceous Earth Filters (commonly called D.E.filters).  With all types of filters, size matters. Your filter must be the correct size for your pool. Your Pool Pro Professional can advise you on the pool filter size required for your pool and can inform you on how to clean and maintain your filter.

Firstly let us explain what a micron is. A micron is a metric unit of length equal to 1 millionth of a cubic metre. Each type of pool filter filters particles out of the water. The most effective are those that filter to the smallest micron.

Cartridge Filters

Cartridge filters are mostly used on small pools and are commonly used on above ground pools. They are less expensive than sand or D.E. filters, however they are not as effective in filtering small particles. They will filter particles to about 25 microns depending on the cartridge’s capability. This is an estimate only as different manufacturers make different claims.

These filters must be cleaned regularly. Pools with cartridge filters occasionally become cloudy due to the filter’s inability to filter out the smallest particles. In this case the use of a clarifier will coagulate these particles, assisting the filter to trap them more efficiently.

Sand Filters

Sand filters are now the most commonly used filters in swimming pools and are easy to clean. Sand filters simply get backwashed, which washes the captured dirt out of the sand. The sand in these filters should be changed approximately every 7 years or so. Your Pool Pro Professional can ascertain when this is required.  

In general sand filters filter smaller micron sized particles than a cartridge filter can.  If Pool Pro Zeolite is used in place of sand, it is said Zeolite will out-perform the sand in a filter. When replacing Zeolite in your filter, the used Zeolite can be used as a fertiliser on your garden.

D.E. Filters

Diatomaceous Earth is mined and is the fossilised remains of microscopic shells created by one-celled plants called DIATOMS. Although D.E. filters are not as popular as sand filters, these days D.E. is known as the most efficient filtration of all and is used as a filter media in food.  They are more expensive than sand filters and are a little more time consuming to look after. Following back washing, new Diatomaceous Earth needs to be added.

For more information on filtration, contact you local Pool Pro Professional.