Hi guys,
Sorry if this has been answered recently but I have noticed lots of tiny black dots appearing around the face and top side of my newest discus - two 7cm white butterflies. They were perfectly white (with blue fins) with no speckling when they arrived and have since developed what looks like pepper on the top quarter of their bodies. What is the likely cause and will it go away or is it permanent?

I did spot treat the tank with syringes of strong hydrogen peroxide to treat a cladophora algae problem I was having a couple of weeks ago, but the fish didn't seem to mind at the time. The dose rate was roughly 35ml of 50% hydrogen peroxide into a 900L tank, which isn't too high from what I've been told. Would/ could this be the cause of the peppering or is it more likely something else?

Two weeks ago


Now