Two Little Fishes KW-300 Kalkwasser Reactor. The KW Reactor 300 creates saturated kalkwasser solution every time the feed pump is switched on to replenish evaporated water. Gentle mixing is achieved with a rotating sprinklerhead that is powered by a powerhead (not included). Recommended to be used with top off system like ATO by JBJ or Tsunami AT1 and a powerhead ranging 200-300gph. Specifications: * Capacity: Use with up to a maximum of 1 cup calcium hydroxide. * Aquarium Size: One reactor for aquariums up to 300 gallons (1135 Liters). * Recommended Pump Size: ca. 200 - 300 gal/hr (760 - 1140 L/hr). The pipes automatically reduce the flow to a small stream. * Connection for Hoses: 1/2 inch (12.7 mm) i.d. The inlet and outlet flexible 90° fittings rotate to suit your installation.