Re: Copper.....safe? Or not?
Copper like most meds has good and bad effects. In almost all cases medication is best done in quarantine tank and outside of the main display tank. In the case of copper one of the biggest side effects is that it kills almost all invertebrates including snails etc. IMO opinion it should NEVER (as soon as say this I will find an exception but basically never) be used in the display tank. It should be used carefully in a QT tank. One area that I tend to stay on the soap box is that people need to understand the full effects of whatever they dump into the tanks. In many cases people have unknowingly turned the fish tank into a giant chemistry experiment. If you have already used I would not plan to keep any invertebrates fro a very long time (maybe ever) and intro them very slowly to see if the effects have diminished sufficiently that they can live. For treating ich, I would suggest the salt treatment described in the sticky article.
24 Gallon Salt Aquapod
20 Gallon Freshwater
Various QT tanks
2 x 75 Gallon Reefs in planning stage