Use Filter Clean to soak your filters clean or spray and rinse Method 1) Mix 16 ounces to 2.5 gallons of water and submerge the filter. Soak filter for 30 minutes or longer, remove and rinse. Method 2) Spray Filter Cleaner into the pleats of the filter. Allow cleaner to stand for 15 minutes and rinse. Typically, Filter Clean should be used monthly. Sanitizing system, frequency of spa use, filter size, and other factors may require more or less frequent use.