D.E Filter Cleaning and Maintenance
D.E. filters are in our opinion the best filtration system available. D.E. is an acronym for Diatomaceous Earth which is a naturally occurring type of rock that is crushed and used as a filtration medium, meaning that it actually coats the filter panels inside the tank and the water is actually filtered by the D.E. as opposed the the weave of the panels like in cartridge filters. The maintenance of these systems is typically significantly less than cartridge filters which we recommend be cleaned at least every other week.
Our recommendation with D.E. filters is to perform a backwash and refresh the D.E. every 3 months or 10 psi pressure rise in the filter and to do a full D.E. teardown annually depending on use, pool size and level of service. If a pool has turned green for a week or two we recommend a backwash to refresh the filter, any longer we always recommend a teardown to remove the old D.E. which may have become too dense to pass enough water or be removed by a normal backwash cycle.
We have mentioned backwashing and teardown’s which sound particularly similar as they both serve to remove old D.E. which is true but the methods are very different. Backwashing is a setting on the filter valve usually opposite of the regular filter position. What this does is reverse the flow in the filter and blow off the D.E. from the panels. The waste then flows out through the drain pipe the comes off the D.E. valve. After backwashing until the water runs clear put the valve into the filter position and add fresh clean D.E. into the skimmer, the exact amount needed will vary depending on the size of you filter.
To add new fresh D.E. turn on the system to ensure the lid is not leaking and make sure your skimmer is running s this is where the D.E. must be added. Now the exact dose varies from filter to filter but we always recommend adding one scoop of D.E. and then waiting a bit before adding more. What this will allow is time to check the return jets in the pool. If any milky white water comes out there is likely a tear in one of the panels and it must be found and replaced as eventually all the D.E. can go through this hole making the filter incredibly ineffective.
Teardown’s are a lot more involved of a process. This is when the filter is actually opened and the panels inside are removed. These panels are usually in an interlocking spiral shape which if you are unfamiliar with can become frustrating to reorganize so take a picture before you separate them to help with reorienting them. Once the panels are removed and separated they must be completely hosed down to remove all D.E. oils, hair, pollen and whatever else may have been sucked and stuck onto them. Upon being cleaned inspect the panels for damage. The kind of things to look for are broken ribs, any tears in the fabric or brittleness of the plastic and fabric. Broken ribs cause tears, and tears cause D.E. to get back in the pool which gives it a strange milky white appearance and mounds of D.E. once the water settles. Replace broken or worn panels, and put it back together the same way you took it apart. Be patient as they can be finicky to get back together, but it will eventually all come together. Once the panels are clean and put together, lubricate any o-rings and place the unit back inside the tank making sure its sealed and secure. When you put the lid back, if you have an older filter, we recommend a rubber mallet to tap the metal belly band to get it nice and secure. Most newer D.E. filters shouldn’t need this step but always ensure the filter lid is secure.