stunted growth?

[Nano]

So over the first threeor so months I had my tank set up, I had good growth one birdsnest wad growing 1/2"-1" per month and the monti caps were doing about 1/4"-1/2" per month. Then it seems about April things just stopped growing. And are still that way today. I'm not sure what's going on or why, I'll have to test my params tonight when I'm off work, but thought I'd ask what could be causing it, the only things I'm feeding/dosing are seachem calcium, and mag, and reef roids. Which for the most part keeps the water where it needs to be, last test was on friday, and params were
CA 430
Mag 1320 +/-
Alk 10
Nitrates and trites 0
Ammonia 0
Phosphate 0
Salinity 1.024

This is what I always test at sometimes the ca and mag are a bit higher/lower depending on when I last dosed. The lights are now up to 75% and I notice improvements in color but still no growth. Do I need to feed or supplement something else as well or do it differently? I'm using IO reef crystals .

It's just getting frustrating I keep looking in and taking monthly pictures of coral but notice little or no difference. It's to the point where I'm just thinking about selling off the live stock and getting a bunch of angels or something.