Carbon Dioxide Feeder Single Tank With Bracket 120V Neptune Benson 11473 11473 The safest way to lower pH! No more hazardous acid to handle or smell. CO2 feed units are a safe alternative for pH control in pools and spas. They eliminate the handling hazards associated with muriatic acid. They also prevent the danger of accidental mixing of chlorine with acid. The Neptune Benson CO2 Feed System increases the longevity of pumps, filters and other pool equipment. It is for a single tank and takes pressure gauge readings.Includes 120V solenoid valve for remote on/off control of CO2 feed, CO2 Diffuser Assembly and bracket. Single tank regulator is sold separately.