Pleatco's FilterWash™ Spa Filter Cartridge Cleaning Tablets are the most up-to-date improvement in making your spa maintenance that much easier. Simply drop a tablet in a bucket of water and in 25 minutes your spa cartridge is clean! The tablet will fizz up and will release body oil, lotion, soap scum, grease, and dirt from the grimiest cartridge. No measuring, no splashing, and this environmentally friendly tablet is safe on any type of spa cartridge.