How do aptaisia spread?

[Fish]

I am afraid that I already know the answer to this, but is there any way to keep aptaisia in the sump without them spreading to the display?

I got the idea from Paul who said that Calfo cited them as being great for nutrient export. I know that there are a lot of safer ways of going about it (chaeto for example), but Tim has already told me that he would sell my old mantis shrimp, Ike, back to me when I was ready. The idea of having Ike in the sump with a forest of aptaisia appeals to me. Kind of like the H.G. Wells story 'The Time Machine', with the Elio and Morlocks - a beautiful and peaceful world up top, and a dark and scary world down below.
I first got my mantis shrimp back when they were viewed as being "reef tank enemy #1"; however, it turned out to be the most rewarding animal I have ever kept. They really have come in fashion now and the number of stomatopod owners has gone through the roof.

I don't think that aptaisia will ever gain in popularity, but just in case, would you mind calling them glass anemones instead? Sounds nicer ( :

- Chad.

Even if it isn't safe to share the water supply, I am considering setting up a seperate tank dedicated to "unwanteds" - Aptaisia, flatworms, bristleworms, with the mantis shrimp ruling over them all.