I read in the freshwater encyclopedia it absolutely ruins your BB. Does not seem to be the result with people here..brianp;3354240; said:It's certainly true that copper is toxic to inverts. However, that aside, personally, I think that the negative claims against copper are largely exaggerated and unfounded As a matter of fact, copper is an effective ectoparacide (among other things) and can be used to treat a range of parasites (including ich), without staining silicone or acrylic as other medications will do. It is cheap, easy to deploy and will not harm biological filtration. Can you imagine spending several thousand dollars on a new acrylic tank and then seeing it discolored blue or green because you treated an ich infection?

That's a Cardinal sin of the Nth degree in reef keeping.