+1 on everything AHD said.
If bulbs are 6-8 months old, i assume T5? if not cooled and not a high end bulb they are starting to lose their push and they are losing color spectrum as your bubls lose spectrum, so do your corals
Cooling bulbs is huge, when AHD cooled his and told me results I put fans in and had to raise the lights 3 inches due to burnt tips.