Periodically you have to clean the debris and contaminants out of your Hayward DE Filter. This process can be done at three levels: 1- by backwashing the filter; 2- by extracting and cleaning the grid assembly; or 3- by extracting and cleaning each grid in the assembly. For more information on Backwashing, see our guide on "How To Backwash a Hayward DE Filter". For a more thorough cleaning, you can extract and clean the grid assembly about twice a year. For more information on clean the grid assembly, see our guide on "How To Clean a Hayward DE Filter Grid Assembly". For the most thorough cleaning, you should pull the Grid Assembly and take it apart to wash down each Grid individually. This guide addresses this last procedure.