That sounds ok, but I think that 2 MH in a close proximity will heat up your tank. One should be enough. 250 watts of MH is really alot. It is not the same as 250watts PC or VHO. MH are lot more intense, partly because of concentration of lighting on a smaller area. A MH bulb is about 6-8 inches, as oppossed to 24 inches for a PC.