Pond One ClearTec 9W UV-CMax Pond capacity 6000L, Includes: 10M cable, 9 watt bulb, Quartz sleeve Micro switch in cap, Maximum flow though rate: 3000 LPH Max Pond capacity 6000L, Includes: 10M cable, 9 watt bulb, Quartz sleeve Micro switch in cap,Maximum flow though rate: 3000 LPH Quality in line sterilizer ideal for aquariums, ponds and hydroponics The UV C unit should be placed after your filter, so that the water comes from the tank through the filter then from the filter