Flower Pot Coral

[Crawdaddy2003]

Any reason why they do this? A test kit I have is telling me that all my water values are fine...

 

[SkiFletch]

Sadly nobody knows for sure. There are lots of theories, but nothing really well-supported. The only thing we as hobbiests know for sure is that Goniopora tend to bleach in captivity and have poor success rates.

 

[Opcn]

They expell Zoox because the params aren't what they need, the cnidarians can handle wider params than the zoox and when the zoox start dieing the cnidarians purge them so that the toxins don't kill whole polyp. Corals cannot regrow zoox they have to recapture and culture them, some say that having an unbleashed colony of zoox will help the bleached colony recover.