UV won't kill all the ich, it may get some of the free floating ich but it will remain on the fish and in the sand/rocks. You have ich because you didn't quarantine your fish and now you need to set up a large hospital tank treating with either hypo or copper, I would recommend hypo but you need to have a refractometer. You have several fish in there completely unsuitable for your tank, scooter blennies live off pods and need larger tanks with lots of live rock, they will probably starve to death if they don't eat frozen foods, the hippo needs a tank size of at least 125 gallons which a little amount of research on your part would have taught you. Repost this in the disease forum and list all your water parameters and how you are testing them i.e. dip sticks, what kind of test kits, hydometer or refractometer, plus how long this tank has been up.
