lower phosphates!

wait after posting that i went back to clean up the test kits and the ammonia did turn a little green like .25 where could that be coming from

 

Personally I do not like large substrate and if it were my tank I would start the process of replacing it, by removing roughly 1/4 of it at a time, to allow new substrate to become seeded. How deep is the crushed coral substrate? You have to be careful when disturbing deeper sand beds.

You ca level is on the high end but not too high. I keep mine around 450 but I have mostly stony corals.

Your salt maybe low in magnesium that is not unusual.

I am not familar with de nitrate in the carbon reactor so I can not address that.

Looking forward to the images.