ich question...

[gurgle]

I have a 18 watt uv on my 75 gal. tank. My question is though, should my uv kill the ich completely, or does the ich keep cycling & come back again?:notsure:

 

[elfdoctors]

A uv sterilizer will not eliminate an ich infection. It will lower the population of free simming ich so your fish may be able to survive a low level infecton. Most of the free ich (not attached to fish) in your tank is in your substrate where a UV filter can have no effect. There are no diseases that a uv sterilizer will eliminate.
There is even some debate that these may even be harmful as they also kill off some of the beneficial bacteria. This is not an essential piece of equipment.