well there is a thought thats why i cant get my nitrate dn even using a lot of vodka that vsome how the bacteria are zapped or the ethenol changed but guess what i never had a crazy breakout of ich velvet or anything but occasional flukes . so ya expensive fish , i wouldnt be without it . i will tell you also it keeps water clearer also . one time for about 72 hr period bulb went out . when i replaced it , i saw big light pennetration ans clarity change especially looking through sides of tank . now i bleached out some coral from this but that is just the change thing with sps .