I have glowfish, and tried the black light in a few different ways.
LEDs do the best at not making the water look milky, but are difficult to find, you basically have to do it yourself and they're hard to get an even glow.
The fluorescent or CCL tubes make the water look milky, even if its not dirty by normal standards. My friend told me its literally fish urine. I don't know, but it made my water look extremely dirty.
What I found as the best solution is blue LEDs. It makes the glowfish glow better than any of the UV lights did that I tried. So, just buy a pretty bright blue LED moonlight kit, and it will work best. Just turn it on when the normal lights aren't on so you can see them glow at night, they won't glow during the day unless you have super bright lights. Although the blue LEDs work best on the "green" glowfish. They don't light up the red or yellow ones quite as well, but the green ones get very bright.
Hope this helped.