Backwashing a pool filter is the process of freeing the filter of dirt and debris it has collected during operation. The main job of the filter is to prevent small particles of dirt from re-entering the pool water from the filter. Backwashing the filter is an imperative step in proper pool maintenance.
Backwashing Explained
Filters that need to be backwashed use either Diatomaceous Earth (DE) or sand. The process of backwashing involves flushing the filter of either the DE or sand and replacing it with fresh DE or sand. DE filters are more efficient than sand filters and can trap smaller particles of dirt and debris. However, both DE and sand are responsible for trapping dirt particles that are too small to be caught by the pool's skimmer basket and would otherwise pass right through the filter as well.
How Often to Backwash
DE filters should be backwashed once a week. Look for a pressure gauge on the side of the filter. The normal operating pressure for the filter is 10 to 15 PSI. When this level is exceeded, it is time to backwash the filter. Sand filters are only backwashed a few times per season because the dirtier the sand gets, the more efficient it actually is in catching smaller particles of dirt. A DE filter should be backwashed once a week at the peak of the pool season.
Backwash
Both the DE and sand filters have a release valve at the bottom of the filter for the purpose of flushing it out. With the filter off, turn the valve and pump the filter handle a few time to flush all the DE or sand from the filter. Turn the release valve off when the water runs clear. This is an indication that the filter is free of DE or sand. Turn the filter on and add the new sand or DE through the pool's skimmer according to your pool and filter size.
Other Reasons to Backwash
Referring specifically to DE filters, it's wise to backwash the filter after you vacuum the pool bottom. If your routine is to backwash the filter once a week, always backwash after vacuuming because the excess amount of dirt and debris sucked up by the vacuum dirties the DE more than standard circulation.
Tags: backwash filter, dirt debris, once week, particles dirt, sand filters