Hi friends, i just want to know where the 20k works better at the center or at the corners. Yesterday i place an order for 2 ReefOptix lll with 250w electronics ballast and Ushios HQI 250w 10K D/E and two 10k250w S/E Ushios and Two S/E 20k Coralvue bulbs. I want to try the 20k and need some advice of where it works better. The tank is a 72" long 125g tank. Thanks in advance , Ralphyhp.