I have been thinking about adding a secondary light to my setup. Something in the blue/purple spectrum, almost like a black light but w/o the UV (since I read it's harmful). Also, I want a way to be able to see the fish at various times of day, without having to leave the lights on for 15 hrs a day. Are the Actinic blue lights or LED "moonlights" good for this purpose? I want something that looks good on the fish, but won't cause algae growth (outside what my "normal" light does) and can extend viewing time without lengthening the "day" from the tank/plant/algae perspective.