Again, you aren't going to be able to use a UV to cure the tank of ich. Anything UV that stands any chance of doing this will heat your tank up to the point of killing the inhabitants without a chiller. If you don't want ich, the only way to ensure that is through proper QT practice. There have been countless others who have tried using UV to treat a tank with ich, it didn't work. A UV can help with ich but will not cure it in a tank, unless it is vastly oversized then there are other problems associated with that