My tangs are itching like crazy and are starting to get blotchy. I stopped feeding nori for a couple weeks to try to encourage them to eat off of the rocks however I just started them back on it a few days ago. Can anyone tell me what my problem is? My house was also just painted a few days ago as well but the tank was taped up pretty well but it is a rimless tank so could that be the problem? Any thoughts would be appreciated.