Pentair UV makes two distant series of UV lights;
The Sterilizer Series come in input wattages of 18, 25,40 and 65 watts. These are all single bulb units with 1 1/2″ union PVC slip connections.
Sterilizer Series UV’s are designed to achieve optimum germicidal disinfection, protecting your valuable Koi against harmful waterborne pathogens.The design of the UV Sterilizer Series is the result of a calculated balance between equipment size, cost and performance; making UV Sterilizer Series the best option for Koi Pond disinfection for smaller ponds and flow rates. The Sterilizer Series are also GUARANTEED to clear green water in 3-5 days if sized and installed correctly!
The High Output Sterilizer Series come in input wattages of 50, 80,120,150 watts. These are all single bulb units with 2″ union PVC slip fittings.
High-Output Sterilizer Series deliver optimum protection against harmful pond pathogens and destroy green water algae. They feature our high-output T6 style UV lamps, offering approximately twice the UV lamp output when compared to standard low-pressure UV lamps of the same arc length. With the increased UV output, The HO UV Sterilizers offer increased performance in a unit that requires less space. Each HO UV Sterilizer model is designed to operate safely in wet environments and they are UL listed. HO UV Sterilizers are designed for Koi ponds and light commercial applications, filling the gap between our standard and commercial models, and are ideal for larger Koi ponds from 4500 gallons to 15000 gallons.
Before Selecting a UV Light
Before you select and purchase a UV light I would highly recommend that you read this article Properly Sizing a UV Light. This article will will teach you a little known secret on how to get the smallest and thus the least expensive UV that will work to clear green water once and for all. Uv lights are expensive so there is no use buying one larger than you need. This article will help you to save lots of money and make sure you get the size UV that will work! A properly sized and installed UV is a 100% fix for green water.