Sorry I haven't been around this past couple weeks. I like the spread and color better on the Skys vs the XR30s, but they both produce PAR within 5% of each other. XR30s are brighter right under the light and the Skys have better PAR around the edges. I run them full blast for sps, but I think three would be perfect for a mixed reef as I was considering adding a 4th or perhaps an Orphek OR3 bar for the sps. Run them 75% or so and I bet you could grow whatever you like anywhere in the tank without it being too much. Hope you get it figured out if you haven't already!