That coral in the bottom left of the pic looks good, how long have you had that one?
That is a brain coral that I have had for four months.
Lighting? How close are they to the light? Magnesium lvs?
They are probably 13'' away from the actual bulbs. I am not sure what my magnesium levels are, I do not test or does magnesium.
Are you dosing alkalinity?
I am dosing alkalinity, I think it has been pretty low lately, I am working on getting it up right now it is 9.3
Ph is also very important
My PH is good, usually around 8.3-8.4, stays very consistent.