I added corals at different times to all my tanks, depended on where they were in the cycle and how the algae was growing in the fuge. I also run carbon and gfo on all my tanks as well as using bactiv 8 each day/week:
My 60 frag I added corals at 3 months or so. Started with live rock that had been cycled already, added a bio additive, and had no fish until 6 month mark in it. Had calerp in the fuge grow crazy for months and added display algae as well. Added first sps at 6 months, first acros at 9 months and seeing good growth.
My 30L I started with cycled live rock, added a bio additive, added fish and nems within a week. I also let the algae in the display grow crazy and had a nice fuge area as well.
My old 65 I added corals too soon to it, didn't start with cycled rock and didn't use a bio additive.