Garlic is probably just a myth, not studied to actually cure anything, but it is a good thing for fish to eat. I'd get a UV sterilizer, for benifit of the water quality if anything.
"UV's help in several ways.
First is to kill pathogens which effect livestock negatively.
But...we aren't concerned with that here.
UV's are very efficient at breaking down the organics that are accumulating for more efficient export.
UV's do this by breaking down long molecules by ionzation
UV's are great at breaking down coral warfare chemicals and a lot better at breaking organic bonds that would discolor water.
hth,
Sean"
I don't have a UV sterilzer because I plan on upgrading and I'm done spending money on undersized units and don't want to buy too big of a UV kit for my tank. But I do think they are a good idea for fish's health and water quality. I'm thinking about buying one for a hospital/QT tank so I can always have one on hand.
I've never used on not even in my hospital tank. I don't ever have more than a fish or two in there at any one time anyway and they are always new introductions. IMHO if you leave your new additions in hospital from 6-8 weeks and don't feed live foods you won't introduce any parasites , bacteria etc. to your tank," I haven't anyway." I've only bought 2 fish in the last year anyway.
fwiw
chris