For the best hot tub filter cleaning solution our filter cleaner is a powerful alkaline formulation for the removal of oils grease and other debris from spa filters and hot tub filters. Spa Cartridge Cleaner or Filter Cleaner is a powerful blended cleaner specifically formulated to remove oils, minerals, organic matter, and dirt from Cartridge Filters. These deposits clog the filter and reduce filter efficiency and water circulation. Spa Cartridge Cleaner removes these deposits and restores filter efficiency and the lifetime of the filter.