Although acclimating to your lights are a good idea, just wanted to share my experience. I ran halides for a couple of years, and now run Radions. Currently my Radions are at 85%. How this applies to you, my RD is growing out of the tank. The base is maybe 6" under the surface. Mine LOVES being blasted with light. It grows an inch a month easily. Last time I "fragged" it, I took off (2) 14" branches. I would suggest higher in the tank with ample flow.