So I am getting back into the hobby after about 20 years out. I had (2) 125Gal Salt water tanks back in 1989 (ok longer than 20 years). A divorce forced me to quit for a while. Man have things changed. So I've purchased a 150 Gal (48 x 24 x 24), I have a 40 Gal sump tank. I have purchased the apex gold and 2 wav power heads. In addition I got the Vortec L1 pump and the Radon lights. My first project is to build a new stand for the tank. The old one was just not going in the house. I'll have that done in a week or so I think (my first time building raised panel doors). Next I want to build a Foam/Rock wall for the back and left side. I need to leave space on the wall for the Wav power heads. The tank is going to set in a corner so the back and left side will have walls behind them. I'd like to avoid a power head on the right wall because it will face into the room (I'd like that wall clear but not a must have). My thought is I'd put one on the left side panel and one on the back near the right side panel. The idea is to taper the wall down and leave an open area for the power heads. I've read they need to be at least 5" down from the water line. Should one be higher or lower than the other ETC. I know it would be easier if the tank was full and I could move them around but I was hoping to avoid putting water in just yet. Any thoughts?