BioGuard Kleen It Filter Cleaner is designed to remove scale/clarifier deposits, dirt, and debris from the pool’s filter. This product is comprised of a dual action formula that can prolong the life of your filter. It helps prevent scale build up and rust. The experts recommend that this product should be used at least once per season to keep the filter clean. Kleen It has been proven to not damage the filter equipment and to be safe for all filter types.