redgold54 4 Posted April 11, 2013 I have a Sunsun 304B canister filter with a 9uv light on a 110 gallon tank. Do uv lights affect (kill off) beneficial bacteria? 0 Quote Share this post Link to post Share on other sites
dnalex 13,633 Posted April 11, 2013 It can, but with 9w, it's doubtful. There have been reports, and warnings, that newly established cycled tanks should hold off on the UV for a period of time. 0 Quote Share this post Link to post Share on other sites
redgold54 4 Posted April 11, 2013 My tank has been established since October/November. I'm fearful of turning the uv on lol 0 Quote Share this post Link to post Share on other sites
dnalex 13,633 Posted April 11, 2013 I think you're alright lol 0 Quote Share this post Link to post Share on other sites
