velvet in my fish only tank

[CoralWealth]

never heard of that but following along.

 

[drstardust]

Hydrogen peroxide is very promising but still in the experimental phase, especially for this kind of use rather than a temporary bath in a glass bowl. I, and probably others who use H2O2, would say skip on this for now since it's velvet that you're dealing with. If it were ich, some experimentation could be nice, but velvet (if you're indeed sure it's that) is nasty and could cause mass casualty. Therefore would recommend using something tried and true like copper. As always this would ideally be done in a QT, but it is doable in a fish only system.