I love them to death!! I worked in a LFS for awhile and we ran one on every sysytem and since all our tanks were plumped togetherif one tank would get sick it would never transfer from tank to tank as well as it makes you never have green water. When i get back and set up my 220 i have a aqua uv 40watt for it, and most people look at me like i am crazy but its big enough that i can shoot water threw at crazy rates and still kill everything that passes by it: parasites, bacteria, algae , everything.