I have two quick questions currently I’m dealing with ich and have been using polyp lab reef medic and it is been working well up until today. I see a bunch of spots on my to spot bristle tooth Tang I am curious if doing a water change and vacuuming, the sand will help and if a UV sterilizer would make a difference I have a 100 gallon tank with corals two clown fish and a bicolor blenny what do you think should be my next step?