Lots of good replies and ideas here. The leather is in my main tank (only tank) so I have to worry about leaching, this is new to me.
Thank!

I attached my colt corals in a simliar fashion as Harvey (newguy) suggested. I had a heck of a time trying to get it attached, until I sewed the thing onto a rock. I removed the line a week later and it attached just fine. Another thing that I tried and had success with was putting the coral in a little container and sandwiching part of it between a couple pieces of rubble... the colt attached within a few days.

HTH
-Rich