"the kessil is set 9" off of the top. The lights come on at 10am and off at 9pm this gives me my max on viewing the tank. For Color it starts at 5 then peaks at 25 then back down to 0. My Intensity starts at 10 peaks out for 4 to 5 hours @100% and back down to off at 9pm. Everything was started on the kessil controller set on acclimation. I've been playing with this for months now because my zoanthids have stretch so far looking for light I even put a small colony on the very top of the rocks 4" down from the light and they recesseded a little. My anemone and maxima clam love the light they are both just over 12" from it. ON THE SAND RIGHT UNDER THE LIGHT I have different types of zoas, mushrooms, acans, small toad stool kryptonite candy canes and Liams polyps my main reason why i came back to the hobby"