adee, i have a 125 but mine has a center cross brace. since i couldnt have a 3 light MH system which would put a light right on top of the brace i had to go w/ two 36" fixtures. i opted for single MH in each since i felt that 4 X 250 would be overkill. in person, the lighting is very even throughout the tank and it will allow me to keep some of the lower light demanding corals away from the 'hot spots'. in pictures, however, you can see the hot spots under the halides