Attaching large coral colonies?

[Albertan22]

So I've got a bit of an issue. After 3 years in my tank, two pieces of flat rock that make up a bridge and cap rock in my aquascape have deteriorated and disolved and are now breaking up, making my aquascape unstable. I'm on the hunt for some replacement pieces at my LFS's, but these pieces being the top rocks of my aquascape have three large acro colonies attached. Does anyone have suggestions on how to detach these colonies and re-attach them to new rock? We're not talking frags here, the biggest of these colonies is probably 10 inches tall and quite branched. I'm hoping that I don't have to break them up and start from frags again.

I've also been struggling to attach a large hammer coral to my rockwork. The hammer grew to the size of a soccer ball, then one day this summer I brushed it with my arm when cleaning and it broke into 5 pieces. I gave away 4 of the pieces, and have been fighting to get the 5th to re-attach to the rock ever since. I've been trying appoxy with super glue like I use for frags, but it doesn't seem to want to hold the larger piece. Any suggestions?

[Aquattro]

I have remounted large SPS colonies before using epoxy. Lots of epoxy :) Cut the base flush so you have a straight narrow base and use a large ball of epoxy. It's best to mount it in a crevice of the new rock, or if you can, you can even drill a shallow hole into the rock to mount it. It will encrust again and if it ends up crooked, will realign going up towards the light.

[whatcaneyedo]

One of the easiest ways of attaching and moving frags around also works well for colonies. Mount short lengths of acrylic rod to the bottom of your coral and drill holes in your liverock to match the diameter of the acrylic rod. Small frags can just be super glued to the acrylic rod while larger colonies may need to have a hole drilled into the bottom of them and then rod glued into that hole for additional strength.

The branching frogspawn would be a little trickier. I've always just wedged mine into a gap between several rocks. But if you want to stick yours to the face of one you could drill a hole, insert a rod and then zip tie the frogspawn to the rod.

Why is the liverock in your tank dissolving at such an alarming rate? Is your pH extremely low?

[Albertan22]

Thanks for the suggestions. I'm not sure what's with the rock. It's only the two pieces, the rest of the rockworks seems fine. The rock started out fairly flat and only maybe 2" thick. I know for a fact that the mantis that haunts my tank created a bunch of tunnels in there as well which probably didn't help matters. The rock is very porous as well compared to the others.