[chwkreefer]

I have used those plastic cable ties for probably going on 3 years. They have worked fine. As mentioned earlier, the fact that coralline has an affinity for plastic helps to cover those things up fairly quick.

What I did in some cases was put some epoxy putty on/around the cable tie to help blend it in with the rockwork. After awhile it all gets covered up and you can't even find the tie anymore. I did that a few times to make a bigger rock out of a couple of smaller ones.