Your pool filter’s job is to capture solid debris; dirt and dust. Knowing that a filter will only catch solid particles is an immensely important point that may save you from headaches and frustration for as long as you own your pool.
Many people think that a pool filter will purify your water, which is not true. Contaminants such as dissolved solids, bacteria, and disease causing pathogens will not be caught by a pool filter.
The three main types of pool filters are sand, cartridge and diatomaceous earth (or DE). While there is no clear cut winner, each of these filters has pros and cons that can be the deciding factor when choosing which type to use on your pool.
Sand filters have been used for thousands of years. Early use dates back to ancient Egyptian and Roman civilizations that used sand to filter their bath water. They are also the oldest filter type used by the swimming pool industry.
Sand filters use sand particles, usually between .018” and .022” in size, which is commonly referred to as Grade 20 or #20 silica sand. As the pool water passes through tiny openings in the sand bed, debris as small as 20-40 microns in size will be trapped (1 micron is equal to 1 millionth of one meter or .0000394”).
If you are under water usage restrictions, then a sand filter may not be the best choice. These filters rely on backwashing (reversal of flow within the unit) to clean the sand bed. When backwashed properly, a sand filter will require little to no maintenance.
Within 5-10 years the sand will need to be changed, which can be performed by a pool owner in a few hours time. Like cartridge filters, filter sand can be rejuvenated by the use of a Sand Filter Cleaner product. Sand filters are relatively inexpensive, easy to operate, and rarely require repair.
Next up are cartridge filters, the new kid on the block, or the youngest of the three pool filter types. Cartridge filters were invented and developed in the 1950’s. A cartridge filter looks very much like the air filter in your car, just cylindrical and much larger.
Pool water is forced through the pleated polyester fabric and the cartridge pleats will trap debris as small as 5-25 microns, a significant improvement in comparison to a sand filter. Another huge draw to this type is maintenance, which is minimal. With a properly sized cartridge filter, you should only have to hose off the cartridge a few times per season. Furthermore, cartridge filters are completely absent of a backwashing procedure, therefore saving water.
Cartridges should be replaced every 2-5 seasons, or 20 or so cleanings. Over time, the pores of the polyester material will become clogged. Using a Filter Clean product will help you to delay the inevitable, but eventually the time between cleanings will increase to an inconvenient level.
If any pleats become bent or misshapen, the top or bottom cap starts to separate from the pleats, or if you notice unreasonably high operating pressure, then the cartridge must be replaced to continue proper filtration.
With a fantastic filtration quality and ease of use, the cartridge filter is becoming one of the most popular choices among pool owners today.
Diatomaceous earth is a naturally occurring sedimentary rock that consists of fossilized remains of prehistoric hard shelled algae creatures, called diatoms. These filters use the DE powder to coat the DE filter grids (or fingers, used in the Hayward Perflex DE filter). Your pump pushes your filter water through the De powder coating the grids, and the dirt is left behind.
DE pool filters are the best pool filter type, and above all others will provide the absolute best water clarity. A pool owner with a DE filter can expect a filtration quality from 1-3 microns! This makes DE filters a very attractive choice, but this practical “polishing” of your water comes with a decent amount of maintenance. DE filters must be backwashed or bumped to help remove debris, gunk, and caked up DE powder.
Backwashing will reduce pressure and restore flow rate, but every now and then the fingers or grids must be removed from the unit and rinsed thoroughly. Also, after backwashing, DE powder must be added through the skimmer for replenishment.
A tricky aspect of ownership is also disposal of the DE, with many cities and towns restricting disposal, some choose to avoid this filter altogether. DE powder is an organic compound, and completely natural, but if you happen to pump too much of it into a small stream, it can choke the water and cause harm to aquatic life.
Even though it is the most expensive filter type to buy and maintain, with its incredible filtration capabilities, you can count on a beautiful crystal clear pool with a diatomaceous earth filter. It is the most superior form of pool filtration.
With each of these pool filter types, cost is going to be directly influenced by the quality of the job they do. Typically, they mimic the order of this article in cost, sand being lowest and DE highest.
When in the market for a pool filter take into account the maintenance level as well. Sand filters are less expensive and fairly low maintenance, Cartridge filters next with a mid-range cost and minimal maintenance, and lastly the DE filters with a higher cost and elevated amount of maintenance.
As you can see, there is no best pool filter type for everyone. Take this advice into account when choosing your new pool filter to assure you get a filter best suited to your needs, in terms of filtration ability and desired maintenance level.
SPP Pool Expert