I think a lot of people, myself included, started dry rock or majority dry rock tanks within the past few years with the expectation of having a solid sps system. And over the past few months it seems that these types of threads have been very common. It seems that dry rock is the one common thread throughout many of these sps and acro struggles. It seems that there's just quite a bit more to growing sps, acros especially, than light, flow, and water parameter stability. From what I've worked out it all comes down to nutrients. In immature tanks algae and cyanobacteria out compete corals for available nutrients. Truly mature sps dominant tanks seemingly have almost zero issues with algae or cyanobacteria, and all those nutrients just get sucked up by the corals. My bet is that this is all based on some bacterial balance. But I'm only guessing, and I don't know how one arrives at this point quickly and consistently. My tank has been up for 9 months and I'm still struggling to get to a point where my acros are happy, let alone growing.