For initial use in holding tanks/porta-potties empty holding tank or porta-potty and rinse with fresh water to remove previously used chemicals. Tanks to 30 gallon capacity: add 10 ounces of Tank Tamer through head and flush with sufficient amount of water to cover bottom of tank. Tanks in excess of 30 gallon capacity: use 1 ounce of Tank Tamer per gallon capacity of tank according to the previous instructions. If system is unused for more than One (1) week: add 4 to 8 ounces of Tank Tamer to system to refresh bioactive process. Automatic Treatment Systems: Fill reservoir with one (1) part Tank Tamer to three (3) parts fresh water. Mildew/Mold stains: apply Tank Tamer full strength on moldy or mildewed surfaces including fiberglass, sealed wood, plastic and tile (test in inconspicuous area before using on colorfast fabrics). Allow sufficient time for product to penetrate fungus then wipe down with damp sponge or cloth. Rinse thoroughly and repeat application as necessary. Do not use tank tamer in drinking water tanks. Use in waste holding tanks, porta-potties and recirculating toilet system only.