Duncan Advise

ghinch23 · 2026-10-26T18:46:39-0400

Looking for advice on a Duncan coral that isn’t looking too good.
All other corals in tank look good. My euphyllia look the best they ever have. No obvious reasons for downfall.
Parameters:
Alk-8.8
Mag-1350
Ca-430

1.0255 salinity

All my parameters have been steady for months. And this coral was grown from 2 heads to many.

Recently added an emerald crab who I have not seen bug this specific coral but he has been all over my Digitata. Not sure if it has been agitating it. Tailspot Blenny is the only other tank mate that I have seen chomp a coral.

For 1-2 days the Duncan was closed, now day 3 its neon green base is looking splotchy/ loosing color. If it was just closed i would be less concerned, however the loss of color raised a red flag.

Any advise?

Saltyreef · 2026-10-26T19:14:08-0400

ghinch23 said:
Looking for advice on a Duncan coral that isn’t looking too good.
All other corals in tank look good. My euphyllia look the best they ever have. No obvious reasons for downfall.
Parameters:
Alk-8.8
Mag-1350
Ca-430

1.0255 salinity

All my parameters have been steady for months. And this coral was grown from 2 heads to many.

Recently added an emerald crab who I have not seen bug this specific coral but he has been all over my Digitata. Not sure if it has been agitating it. Tailspot Blenny is the only other tank mate that I have seen chomp a coral.

For 1-2 days the Duncan was closed, now day 3 its neon green base is looking splotchy/ loosing color. If it was just closed i would be less concerned, however the loss of color raised a red flag.

Any advise?

Emralds are hit and miss for controlling algae. Ive had best luck with mexican turbo snails for out of control algae issues.
I would remove the emrald and see if the duncan bounces back. 3 days of being closed after a new crab addition may be a telltale sign

saltwaterfish.com · 2026-10-26T19:16:19-0400

If parameters are stable it's hard to tell. Try putting a cage around your duncan made of eggcrate or netting and see if that helps after a few days. If it does then that means something is picking at it and making it ticked off.