Green Star Polyps spreading without contact?

[Dez]

I have a mainly sps dominated tank, but I have a love for Green star polyps because they are so bright. i have a rock on it's own that is on the sand bed with green star polyps.

Is there any possible way that the GSPs will just pop up somewhere else in the tank? I don't want it becoming a pest later on down the road like xenias.

Anybody have any experience with it just popping up out of nowhere without physical contact of another rock?

I know that xenia, and musrooms and even colt corals will have a tendancy of just popping up somewhere else in the tank.

How about zoo's. If I find some bright coloured zoo frags I might start a zoo garden on a seperate rock on the sandbed if they won't just pop up elsewhere.

Thanks in advance.