Hollywood stunner STN

[lapoza]

I got a very large piece of Stunner coral from a LFS back in Early December. Within the last 4 weeks it has slowly started to STN on the back underside of the coral and is now creeping to the front side. I did have to remove the piece from my tank to catch a sick fish at the end of January, it was outside of the tank for roughly 20 minutes. I am not sure if it doesn't have enough flow, if the light is too intense, or if my Alk was too low.

Also curious if once it starts to STN if it can be stopped without fragging. It is still growing fine overall but dying at the same time if that makes sense

 

[Hemmdog]

What’s your parameters

 

[lapoza]

Alk 8.5
Phos .15
Sal 1.026
Calcium 520

 

[Hemmdog]

Alk 8.5
Phos .15
Sal 1.026
Calcium 520

Magnesium? Nitrate?

Calcium is pretty high. Things could be out of balance. Mag will determine that.

 

[Softhammer]

I wouldn’t worry. Those corals are probably hands down the fastest growers I have ever seen. That underside tissue recession is normal as the coral grows and shades itself. If you are worried though, it’s always a good practice to keep a frag for preservation purposes in case it does get worse.