I was thinking of using 4 pc fans also it will be the first grow so very new to it. I will prob start with two 150 clfs just to get me feet wet then move up as I go along. I figure I can always keep it as a veg box and then build a bigger one with a 400 hps. Or do you think I am wasting my time with two 150 clf they should put out 16,000 lumens and I think that is equal to a 150hps. Any help or sugestions are very helpful.