In reply to Mopar9012....NO ,not at all too much spillage of light.As stated, it is set Now @ 20% max light output for the PM. It will later go over my 60 cube. Logan,at Reefbreeders, said sart it at 20% max light and work up 10% a week(so not to shock fish or corals). Coral colors really are stunning under this light and you get great shimmer! My optics are 120. No heat transfer to my cube. Love this light! Eventually, I will get the mav % to 60 or 70. 2 year warranty...can't beat it.