Features: * TetraPond GreenFree UV clarifiers provide permanent control of suspended algae which cause green water * Heavy algae blooms are removed in most ponds within five days, keeping the pond algae free * This means water clarity is improved while reducing pond maintenance * Each unit is compact, durable, easy to install and energy efficient * The most efficient flow rate is 50 percent of total pond volume * The UV Clarifier is not submersible and should be brought in during the winter months when temperatures are at or below freezing * 1800 gallon maximum pond size * 900 gallon maximum flow * 1/2 in., 1 in., 1-1/4 in. tubing size What"s In The Box: * Tetra Pond 19520 9-Watt UV Clarifier