Originally posted by bboersma79
So according to the rep at the pet store, the 72G oceanic shouldn't require MHs he said they are unnecessary and that my tank can support anemones, corals, etc. with power compacts alone, the depth of the tank isn't too deep to where MHs would be required.
He might be correct but pc will limit you on the corals, and dependin on the depth of ur tank the type of anemone you can have. Clams pretty much forget. I have had friends use pc lights and some have had pretty good luck, but they know to stay away from the light intensive corals/animals. If you know what you want in the way of corals and anemone and pc will be enough then go that route for sure. If your unsure, or want to have light intense corals save yourself some serious frustration in the future and go MH.
It sounds like u have a glass tank, if so you might be able to retro the plastic hood with some ingenuity. A couple of fans to push air will help and a inside box to asborb the heat to not melt the plastic. Your not going to hurt the corals by putting the MH 8 inches from the water, and MH bulbs are insullated twice so they will take a pretty good amount of abuse for spray. Heat, as mentioned before is your concern, MH that close to the tank will warm up the water so u might end up needing a chiller....
I have an acrylic tank, and its a bad idea to get the acrylic that hot (my orginal canopy was only 6 inches from the top of the tank). The solution I came up with was to build a spacer box, paint it flat black and put the canopy on top of it. It wouldnt be my first choice but it doesnt look bad and serves it purpose well of reducing the tank temp. If yours is glass you really only need to worry about the water temp though.