Looking to place lps corals across the top of my rock work and trying to work out what percentage to run my reef led 50 at. It’s on a 20 gallon high. The light is 15cm from water surface and the closest coral will be about 10cm below water surface. At the moment only have some muschroom and toadstool with the lights set at 35% blue and 13% white peaked for 8 hours. Also how much of an effect does intesity have on par. If I cut the intestity in half does this cut par in half?