320 Series - for permanent installation in return line of new or existing pools or spas. Installs in return line on pressure side of pump downstream of all equipment. Standard with 2” slip PVC fittings and adapters for 1-1/2”. Select Feeder Above: R171096 - 320, White body, holds 11 large or 98 small Bromine or slow dissolving Trichlor tablets. Treats 6,500 to 27,000 gallons bottom feed and 18,000 to 70,000 gallons top feed. R171218 - 320 C, Amber "see through" body, holds 11 large or 98 small Bromine or slow dissolving Trichlor tablets. Treats 6,500 to 27,000 gallons in a bottom feed configuration and 18,000 to 70,000 gallons in a top feed configuration.