Eradicating Unwanted Zoas

[JurisHP]

My tank has a ton of these (see picture) that I in the past have cut with cuticle scissors (while in the water) to get rid of (I don't want to get poisoned).

Question: when I cut them and they float away, do they just propagate elsewhere, or are they dead? I don't want them to spread.

 

[EastCoastScaping]

I think when they float away they would die unless they can get lodged into a crevice or hole in the rock work. I would suggest collecting them with a net after you cut them so they dont float around.