Pool Filtration Systems: What are the differences?
When it comes to filtering the water in your pool, you have 3 options: Sand, Cartridge or DE (diatomaceous earth).
Sand Filters
Sand filters are the most popular style due to their ease of use.
The tank is filled with sand or glass filter media (the amount required will differ between sizes / manufacturers – be sure to follow the manufacturer’s recommendations.). As the water travels through the sand/glass media the debris is caught and stays within the media bed until a backwash is performed (typically when the pressure gauge is reading 8-10 psi above its normal pressure). Once a backwash is complete, you will perform a 30-second rinse and then put the system back to filter.
Sand is changed every 3 – 5 years, glass is changed every 7 – 8 years. A sand/glass filter media can trap debris as small as 20-40 microns.
Cartridge Filters
Cartridge filters can trap smaller debris than a sand filter at 5 – 25 microns in size.
There is no backwashing involved when you have a cartridge filter, which also means less water is lost. Less water waste also saves you on chemicals needed. Once the pressure of a cartridge filter reads 8-10 psi above its normal pressure, the cartridge must be removed and rinsed out. At minimum, it is recommended to soak the filter in a cleaning solution at least once per season.
It is best to have two sets of cartridge filters, this allows you to rinse out one set while placing a clean set into the filtration system (no downtime with the pool, you cannot use the pool without a set of filters.) You must let the rinsed-out set to completely dry before using them again, the drying process of the filter allows the fibers to tighten back up so they can pick up smaller particles when re-inserted.
DE Filters
DE Filters are less common than sand or cartridge filter, it could be because these filters take more to maintain than their counterparts, but they can catch debris as small as 2-5 microns, so your water is cleaner and clearer, backwashing (rinsing) is less frequent which saves on water and chemical waste saving $ in the long run.
Once the pressure gauge rises 8 – 10 psi above its normal pressure the filter needs to be backwashed. When you backwash a DE filter you will remove the DE media as well, so once you have completed the backwash you will need to add more DE. DE is added by using the manufacturer’s recommended amount through the skimmer.
Inside the unit there are grids that the DE sticks to, these grids required cleaning at least once per season.
If you have any other questions related to your pool filter, please contact our knowledgeable customer care team members who will happily answer your questions about filtration.