Cutting frag's...

[kari]

How about a hammer drill in a plastic bag to break up the rock? Also, a heavy guage grounding probe might help if drilling right in the tank.

Sorry but I'm not of much help with Colts. I tried fragging an overgrown colt once long time ago with poor results. As for the encrusting type, if its similar to the one I have, it seems easiest to let it encrust onto to the rock of your choice. Then seperate them.

Note:these softies really, really don't admire star polyps. If you have star polyps nearby don't let them spead on the same piece. I found out the hard way

kari