What are your parameters, exactly? Ammonia, pH (has it changed rapidly?) Nitrite, Nitrate. Tank size, inhabitants, last time you changed the water and how much?
What are your parameters, exactly? Ammonia, pH (has it changed rapidly?) Nitrite, Nitrate. Tank size, inhabitants, last time you changed the water and how much?
Peeling skin cen be a number of things from bad water quality, parasites to bacterial.
Any of the fish flicking and rubbing against objects.
What your tap nitrate reading.