I'm gonna +1 maybe you just need more time to create a more balanced biome. I struggled with SPS for my first couple of years. Killed a lot. Now, I can't stop the stuff, growing outta the top of the tank. I don't think I changed anything. Tank just need to settle down. Not scientific, but that was my experience.
What he says. Plus add more established LR from other established systems growing acros. And add more fish!
Fish Pee, Coral's Number One Nutrient Supply, Cut by Fishing
Fish urine plays an important role in coral reefs' food chain—but unsustainable fishing can devastate this natural nutrient flow.
www.nationalgeographic.com