My fish tolerated the medicine well, and although they survived, the tail fin did not visibly regenerate during the treatment, nor even after a month. But the fish has learned to make do - as a lot of disabled beings have to do....With the charcoal filter element out as instructed, the water turns darker, a kind of green brown, and an abundant light brown foam forms on the surface.I really don't know how to rate the medicine, other than the fish survived in its hospital tank long enough that once it could swim almost normally, the other fish quit bullying it. It seems pretty normal in the wild for sickly animals to be treated badly. That is why you should have a small separate hospital aquarium ready, with really nothing other than an good water circulator/air pump.
Rating: [4 of 5 Stars!]