Learn About The Different Types Of Pool Filtration Systems And Their Operation

By Tammie Caldwell


Responsible for keeping the entire volume of water in a swimming pool clear and safe to swim in, a filter is one of the most important machines in the operation of a pool. It eliminates dirt and debris which make the water cloudy and can encourage algae and bacteria growth. Both inground and above-ground pools can be equipped with one of several styles of pool filtration systems, each with its own benefits to the user.

The basic function of a filter, regardless of its design, is to rid the water of impurities so it stays clear and does not pose a threat to the health of the swimmers. All filter types operate on the principle of using a barrier of some sort to physically remove debris from the water. These different models differ from each other in price, upkeep, and in the advantages they provide.

Together, the filter and pump work to keep the water clean and clear. The pump forces water into the filter where the impurities are removed, then it returns the clean water back into circulation the pool. A high-quality filtration system will last for many years and can help keep the time and money spent on maintenance and operation down. There are three types of filters: sand, cartridge, and diatomaceous earth or DE filters, all of which can be used with both inground and above-ground pools.

Sand filters are the most common type. Water is filtered through a sand bed inside the filter which traps debris with a size of 20 microns. They are easily cleaned by simply running water through them in the opposite direction, and the sand can be used for several years before it will need to be replaced. Affordable and easy to operate, they are a popular choice with many who own pools.

Another affordable, low-maintenance alternative is the cartridge filter. The filtering element in this design consists of a removable cartridge which can remove particles as small as 10 to 15 microns. Economical, they have the added advantage of being easy to maintain by using a garden hose or a filter cartridge cleaner to clean them out. In general a new cartridge is needed for each swimming season.

The diatomaceous earth or DE filter offers the ultimate in water clarity and purification, as it has been designed to filter out the most minute particles which are just 3 to 5 microns. Inside the filter is a powdered substrate made from DE, which is a naturally-occurring sedimentary rock with a porous nature that lends itself well to filtration. More work is required to maintain them and they may cost somewhat more, but the speed of operation and efficiency compensates for this.

With any filter design, it is a good idea to choose a model with a larger capacity than the minimum indicated for the size of the swimming pool. This will mean one has to spend less time cleaning the system. Also, it's helpful to opt for a set-up with minimal pumping, as this will reduce costs for electricity needed to run it.

Basically, the filter one selects for their pool should reflect their priorities. If the user's primary concern is a simple design which needs minimal maintenance, either a sand or cartridge filter would be suitable. Whereas those who are focused mainly on having the clearest water possible, should go for the DE filter.




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