What form of carbon dosing were you doing? Also, why did you decide to stop? Were you dosing any bacteria product with the carbon?
No more real estate? Time for another tank of some sort (frag or otherwise)
I was using vinegar for years and used Zeo bacteria. I stopped cause I started having some cyano issues and decided not to dose while I took care of it. While not dosing I let my Alk creep up a bit and noticed my corals were looking better and the cyano stopped. Keeping a close eye on NO3 and PO4 I realized that nutrients weren't really an issue. It's been a few months now, and things still seem better. I'm not sure where the improvements were but my life is easier and my tank is happier so I'm rolling with it.