I don't see why it wouldn't work OK. I probably wouldn't use the glass tops due to the heat buildup though. Maybe suspend the fixtures over the tank as pendants? As long as the fixture will accomodate aquarium bulbs and I don't know why it wouldn't, it should work...you'll have to buy bulbs as I'm sure you already knew. The ones that come with this fixture won't be suitable for aquarium use due to their color temp. I'd get more opinions before I bought one though. There are folks on here who have forgotten more about MH
than I know at this point 8O . Keep us posted...sounds like a GREAT deal to me.