zoanthids are pretty hardy little guys. I agree with TC, do a couple small water changes to keep the levels from getting too crazy and they should be fine.
Alternatively you can keep them in a bucket with fresh SW
and some lights till your cycle is through if you are really worried about them.
EDIT: You are done cycling though aren't you. IME zoanthids will get the light they need. I have seen them stretch up like 2 inches to get the light. They look uglier then heck, but they survive. If you aren't ready to upgrade your lights, I wouldn't worry about them.