UV sterilizer

[frag!]

Hi everyone. I posted in the equipment section with no response so I am hoping for better luck here. I have a question on a UV sterilizer for a 300 gallon system. I was told you had to be careful with what size you get because you can wipe out the beneficial organisms that exist in our tanks. I bought a complete used system that came with the coralife 18w UV sterilizer. Would this suffice for my system or should I get a bigger or different system? Are they even beneficial to have? Thanks for any advice.

 

[butters417]

id go bigger, i have a 57 watt for my 150g tank. I do not route all return water through it though...its fed off my manifold so some of the return water does not go into it. Its also about how fast you have moving through it...