The Bio UV Professional is probably the worlds best UV system made from 316L Stainless Steel. With a 6" Body and 2-3" returns for today's high flow system. The Bio UV Professional incorporates a single lamp for ponds up to 30,000 gallons, with a long life lamp of 9000 hours. All units are IPS4 rating. Kills 99.9% of algae spores, bacteria and viruses.