Geez, I thought is was almost impossible to kill a colt. It was one of our first corals in the 75g that we set up 8 years ago. The coral was under a pair of 175 MH and grew to fill up over a third of the tank. Finally had to trade it in to leave room for other corals to grow.
Tank conditions at that time were:
- moderate flow
- it probably ate extra food from feeding the fish
- at least having PC lighting
- didn't have a freaking clue about water chemistry then, but would think keeping alk, Ca and Mg up to snuff would be very useful
That's all I can think of at the moment. Good luck with the colt
