Its there for people that are lazy. they buy it, your fish die, you get more, you use the stuff again, your fish die, and it keeps repeating. They jus want your money!
DO NOT buy this junk. It suddenly killed 3 snails in my 30-gallon tank, one of which was 2 inches. I called the company & asked if it was safe for snails. The rather unconcerned reply was "Probably not - it has formulan in it. I think there might be some kind of note on the label, I'm not sure." There are NO warnings on the label, it has the audacity to state on the front "Safe for all freshwater aquariums." Do I smell lawsuit anyone?