Rutrag
Aquarium Advice Addict
On almost every bottle of water conditioner I have seen, it says "Do not use if fish are intended for human consumption." There is something in it that apparently makes us sick........
I think that's a catch-all since anything you give to any animal intended for food is going to be monitored and regulated by the FDA. I haven't seen it in a while, but in the late 80's I worked in the trade and we carried penicillin and erythromycin for aquariums that carried the same warning. I don't belevie it was "denatured" but was labelled as such to keep the production controls off.