I curently have a 40 gallong cube with hybrid lighting, a single XR15 G6 and the Aquatic life T5 fixture. I will be moving to the new Waterbox 125.4 in several months (4' x 2' x 16" high). This will be mostly SPS with the Corals about 8" to 9" below the water surface. I am assuming that a total of three XR15 G6's will do the job. Am I correct? Thanks for the help.