For a start work on Magnesium, Calcium and Kh.
keep them in this range and your corals will go buck wild.
CA= 430- 450
Mag= 1350-1450
Kh= 9-11
and once you can keep them constant then you can look at adding other stuff like Amino acids and coral foods
Is that true for SPS. LPS and Zoas or just the hard coral ?