I certainly don't want to pressure you into using it and then your tank crashes, that'd be terrible. At least you know it can be done with both coral and fish with no casualties. It's the oxygen depletion you have to worry about. A seneye can monitor those levels too. I had put all of the power heads to the surface for agitation, left the skimmer running with no collection cup (it freaks out for two weeks anyway) and I have a sump, which also helps with gas exchange. I also had 35 gallons of water, ready to change, when I used the remover, just in case. That's why I don't want to tell you you'll be fine only to have your fish die because you don't have the same set up. Lastly, when I did the "lights out" tactic, I had put all my coral in a qt tank, you might not have that luxury. Good luck, I hate that stuff.