If you go with metal halide, you should use 2x150W, or 2x175w. A single bulb will have terrible coverage over 4ft. The rule of thumb for metal halide is one per 2 feet.
Truvu 100g Flourite, wet/dry, AHSupply 302w PC, PinPoint controller 10gallon15w T6+15w T8 55gallon40w T6 ODNO4x, no CO2. Discus grow out.
10gallon Tonina tank, 2x15w T6 ODNO 4x
I will do aquascapes after I collect all the plant species and grow them to perfection.
Agreed, 2 MH bulbs would be needed for that tank. I have 2x175MH on my 110x and it covers it well. 1 bulb wouldn't come close to doing the job. I would look more at 150W since bulbs seem easier to come by in different color temp, but you can find bulbs 6500K-10,000K in the 175w with a little searching. In a 2ft tank MH will give you deeper light peniration then the PC (I run both 2x96W PC and the 2X175W HM), 110x is 30in deep.