I treated my ich infested tank, containing three very young, badly infested clown loaches with a single dose of Coppersafe at the full recommended concentration (from the bottle). The clown loaches were apparently undamaged by the copper, and the ich was eradicated. A very robust Java Fern was completely wiped out, along with a bunch of other plants that hadn't been doing so well. Next time, I'll quarantine.... Paul