I have a 150 gallon tank. It is 72" wide and 28" deep and has live plants. I want to get new lighting for it. My question is - if I get something like a 48" 216w T5HO lighting system, will it be enough to illuminate the tank properly. Or does the lighting need to go all the way across the top of the tank? I looked for an anwer on here, but couldn't find one.