UV will do nothing for ich. as far as algae, my one spot foxface and lawn mower blenny clean up any algae. don't mean to scare you away from tangs. many people keep them without problems. if I had a longer tank I would probably have one. with so many choices of beautiful fish I just don't want to worry about my tank becoming infected. yes, ich can infect any fish, but tangs have more problems then most fish. just my two cents.