[addict]

I agree that Colt's are really hardy corals... I've also had one grow out from a miniscule piece of flesh into a 6" tall specimen in about 7 months.

As for the problem you're having, it sounds like you rubberbanded the coral directly to the rock, which is going to cause it to split. Your best bet is to sandwich the base in between two rocks, and 'lightly' band the two together. It'll probably attach to both rocks, but then you can cut away the rock that has the least amount of attachment.

As a bonus, the small piece of flesh left on the cut away rock will probably grow out into another colt.

The problem with banding the coral directly (as you've found), is that it's such a small area pressing the coral down to the rock, that it most often just splits the coral in half... I also doubt the superglue will stick, since the coral will simply 'slime itself off'... it has to attach on it's own.

Good luck.