Hello,
First make sure it’s not stress ick, I have had experience with that, and using garlic guard and feeding more helps. Keep your hands out of the tank and lower lights.
So there needs to be a huge clarification on uv. First off 90% of the uv out there are only what they call a class c meaning it cleans water and makes it clear, that’s it. If you want a uv to kill parasites aka ick marine velvet etc bacteria, etc and viruses you need a stage 2 uv and it had to have 185nm bulbs with a longer exposure time. Most of these are about 4 to 6 feet long. The one I have also has ozone capacity, (but that’s only if your super experienced not only can you kill your tank, but your cat dog and your whole family and yourself). Most of the uv at like pet smart zamzows, even most on brs, and larger fish places are level c. Your standard level 2 or stage 2 sometimes cslled stage A like mine with ozone are (skins was 1400. Some other good stage 2 with out ozone are close to 500-600.