I run mine about 12" off the water, and the reason I chose these over the Radions is you do not need the diffuser to help with the lighting, as the Mitra's use a parabolic deflector like a lot of M/H light housings use, and this way you get better light coverage, and great shimmer without the disco ball effect. They ae both great lights, and I have had both lights and currently set up my sisters 1000 gal. system using Radions. But that was here choice as she bought them thru a friend of ours who owns an aquarium store, and has very little knowledge of the Mitra's.How high would you recommend mounting the Mitras. Any other settings recommendation? I am wondering if I should go with them for my next tank. I really like my XR15 G5 Blue with diffuser, but I am planning on a 3’ long tank next.