For my 4', 75g. I went with 3 AI Sols and I am very happy so far. I researched them all for months but still felt like I was throwing the dice. It is a tough descision. What tipped me to the AI's was that I got a chance to see them in person, play with the controller, and examine the corals that the owner kept under them for about half a year. Do you know anyone who uses LED lighting? My only other advice is to go with a major brand or DIY. It is a big cost and you don't want to have to buy twice.