I'll try that, thanks a lot George.Juano, if you're trying to get the ones with the pink rim only, it will be hard since they are surrounded by the other zoas.
I'd suggest trying to use a scalpel or sharp knife to cut some of the other ones away from the pink rims (like to the right of the bunch up top) to give the pink one's room to grow into their own bunch on one side of the rock. Basically, trim away an area on the rock to give the pink rims some space to grow into.
Once you get them to bunch up, it will be easier to separate them by cutting the rock where the different bunches divide. If you see them start to co-mingle again, try to trim them away again so they don't get mixed again.
If you can, take the trimmed away zoas and put them in a small plastic container with some rubble rock and put them in the sump or a low flow area to try to get them to attach and make a frag of those.