Over my 18" cube, I run my hydra 26 at 100% for the blues, 45% UV, 80% Violet, 85% Green, 40% Red, 67% White. These are my peak settings and I do a simple 2 hour ramp up and like an hour ramp down. My SPS seem to be growing a lot faster than my previous 150w metal halide. I know I run mine higher than what most people run theirs at, but I got to my settings using a par meter to tune the the blue and whites LED's and then adding the green, violet, red and UV until it was at a color I liked. Which I get around 150-180ish on the sand bed and around 3-400 towards the top of my rock structure. In my opinion, it is safe to run hydra 26's at higher percentages. Having a par meter has been so much helpful with LED's and I think everybody who has LED's should at least try and rent a PAR meter, it takes all the guessing out of setting up your lights.