That is a deeper tank and you need to find the link with Par values. I have a 55g with a 2 bulb T5HO fixture with Geisemann bulbs and I get a strong medium light using those bulbs. I can grow all but high light carpet plants and the tank is 17 or 18" tall. My 220g tank is 30" deep and I have to use a combination of T5HO's and Metal Halides in order to get high/very high lighting deep in the tank. So 4 T5HO bulbs might get you into high light. The deeper the tank the lower the par value is at the bottom of the tank so you need to know the par value. I don't have the link but people are often posting a link to a graph that shows all different par levels for various bulbs at different tank depths. That's what you need to see before getting a fixture.