I had a breakout of Velvet in my tank @ November. I ran a diatom and UV sterilizer and thought it would get rid of it. I bought new fish at a great Black Friday deal, put them in my tank (after multiple water changes and running the above) and they all died within two weeks of each other. Some of my other fish started to get really sick but a regal (blue) tang survived (getting cleaned and living by the cleaner shrimp.) It's now approaching March and wonder if it's safe. What have some of you done in a similar situation?