Not the DE expert but you can open and clean the DE filter. I believe if you take it to the pool store, they will soak the screens in Muriatic Acid to clean them. You can do it yourself, but I honestly don't know the safe way to do it that won't damage them, namely how dilute the soaking solution should be, and how long you should leave the screens in, or the best way to rinse them. That should be in your filter's manual. Most of the big filter companies keep manuals on line as well.