Not saying that you wouldn't be better off with MH
, but how long are the lights you have? Do they span the entire tank? If so, they are most likely VHO
. 72" VHO
tubes are 160 watts each. If you have 6 of them, that's 960 watts. Lots of light. There are lots of creatures you could keep under that kind of light. If the bulbs are VHO
, what kind of ballasts are powering them? Are they blue and do they say "Icecap" on them? If so, you can run the bulbs for a year or a little longer between replacements. You'd need three MH
fixtures for a 6' tank and you'd need to probably keep two of your actinic (blue) fluorescents if, in fact, they are VHO
lights. If they aren't VHO
, I wouldn't use them. The best info I could give you for now is to read, research, ask questions, and then do more of the same. Setting up a tank this size is not a cheap venture. If it's done right, you can get years of enjoyment out of it. If it's not set up right, it will be your worst nightmare. We'll be glad to help in any way we can.