Pesky crab or something else?

[bobsreef311]

Hi all, lurker, first-time poster. I have a couple questions about my coral and invert only tank. The tank has been set up for 2 weeks because I had to set up an emergency tank (5gallon) to treat my display tank (37 gallon). I know it's not recommended, but both tanks have been doing well. Anyway, my Duncan coral sometimes shrivels up as if it is getting too much flow or is closing up for the night. And my zoas look as if they are stressed. I was wondering if it could be hermit crabs bothering it that I am not seeing, or if it could be due to this new growth that I have spotted (for Duncan). Another question I recently picked up a coral that I didn’t quite catch the name of when I picked it out and was scared when it was struggling at first but seems to be doing ok. All other corals in the tank seem to be doing fine (GSP, cabbage leather, tubipora, mushroom, and unknown coral) I am going to get the parameters checked at the LFS soon and will keep you updated.

 

[TX_REEF]

Those growths on the duncan kind of look like new heads forming, but I could be wrong.

Did you change anything with lighting or flow recently? If not, chemistry is likely the culprit.