Yes the tank is 36. I don't think I will need lenses the tank is built into a wall so the fixture will be close to the top of the tank. Royal Blue, Blue and White will be the LEDs. Each string will have its own dimmer. My goal is to put the PAR level high enough to keep anything I want. Not that I am going to but I just want to make sure I can. This tank will be a fish only with live rock for some time but I know that in the future I would like to add some easy corals.