Not sure yet. Probably glue some of it, but I don't know what to use. I got some purple epoxy from BRS, but I am not happy with it. I used it to put a couple pieces of branch back together, let it dry for 20 minutes, and they came right off still. Not sure if it was user error or what. Any suggestions would be great.
For some of my larger island.... I drilled some holes and then used some heavy duty black zip ties. These things are extremely strong. I then used a two-part beige colored epoxy. Probably the same stuff as you used...but different color. I then let it cure for a couple of days before attempting to move anything. The smaller island is dry stacked. I wanted some flexibility to rearrange that side of the tank. Of course... now the corals have fused some of the pieces after three years.