Swimming pool filtration systems
How To Choose The Best Filter System
In today's marketplace, there are three different types of filter mediums to choose from:
Diatomaceous Earth (DE) , Cartridge and Sand Filter systems are three mediums that are suitable for pool and spa filtration, but all three have different characteristics. Following is a brief description on how they operate. This should help in choosing the system that best fits your needs.
Diatomaceous Earth (DE) Filtration Systems provide the clearest sparkling water, efficient flow and the largest cleaning capacity for pool and spas compared to sand and cartridge filtration systems. That is because the DE filter removes particles that are as small as 3 - 5 microns. Even though the human eye can't see any particles that are less than 40 microns, increased quantities of large microns can have a very noticeable effect on water clarity. DE filters can filter larger areas, which means longer periods of time between cleanings. Also, DE can be replaced with alternatives such as zeolytes. There are some disadvantages to a DE filter. The initial cost and long-term operational cost of a DE filter is not the most cost effective medium on the market. DE filters require frequent backwashing. DE filters as well as sand filters requires plumbing a seperate sewer line to an area that the water can be backwashed to.
Sand Filtration Systems are one of the most popular ways to filter water. They are simple, effective and require little attention. A sand filtration system will remove particles that are 40 microns and larger. Pool water is routed through a sand filled vessel. Dirt accumulates in the spaces between the sand particles, which causes the pressure to rise. As the pressure gauge rises, this signals you it is time to backwash the system. Another advantage to the sand filter is the low start up cost. Some of the disadvantages of a sand filter are frequent backwashing. Sand filters require plumbing a seperate sewer line to an area that the pool water can be backwashed to. Another disadvantage of a sand filter that particles between 25 and 40 microns can make the water cloudy and the use of a flocculants may be needed.
Last but not least is the Cartridge Filtration System. Cartridge systems have been around for quite some time, but have only recently begun to become popular throughout the country. They offer excellent filter performance and the lowest maintenance. A cartridge is placed in a vertical standing vessel. The filter element strips and captures the smallest particles from the pool water with great effectiveness and provides the longest period between cleanings. When you see the pressure rising on the pressure gauge, simply remove the cartridge from the filter, hose off and return it to the filter. Cartridge filter capabilities are not as strong as DE, but filter out smaller microns of particles than sand. I guess you can say cartridge filter systems are a happy medium.