Can sone one tell me what the white things are? I could not tell if I should be concerned and remove the rock and scrub them off or just get rid of the rock or just leave them be? Please help. Tank has been established for 9 months, 210 gallon. I have been dosing Vibrant for 3 weeks due to an unrelated algae issue but Vibrant seems to have no effect on them. They are white although in the pics they looks like they are blue-ish.