Starbrite - Aqua Clean Water Tank Flush - 1 Gallon - 32300 Cleans and deodorizes fresh water holding tanks and supply systems. Features: Size - 1 Gallon Excellent for use after storage or winterization to completely flush system Use periodically to prevent foul taste and odors. One gallon treats 100 gallons of tank capacity. Directions: Remove all water from tank and system by turning on water pump, opening tank drain valves and opening all faucets and shower heads. After system has fully drained, turn off water pump, close all valves and faucets and shower heads. Add fresh water to tank to fill it approximately 1/2 full. Add appropriate amount of AQUA Water Tank & System Flush required for full tank capacity (1 gallon for each 100 gallons of tank capacity). Add fresh water until tank is full. Move boat or RV several times in order to disperse Water Tank & System Flush throughout water. Turn on water pump and open all faucets and shower heads, keeping them open and flowing for about 3