In need of help from experienced sps keepers!

[ScubaSteve]

Ya, to reiterate what everyone else is saying: Stop. Stop carbon dosing. Stop all/calc dosing.

Just do water changes.

I was helping someone recently who was having similar problems and instantly saw the problem. Pulled all dosing offline and within a week all the SPS were fine. A couple weeks out and they looked great. All tests showed the water beforehand looking fine but I'm 99% sure it was alk swings that were causing it.

Super low nutrients combined with alk swings from dosing is the perfect RTN recipe. If your tank is relatively new, you really shouldn't need to be dosing anything! There's no need to dose alk/calc if things aren't happy (because they ain't growing!) and nutrient levels should be controllable with only water changes and controlled feeding habits (for the first few months at least).