help with hydanophora.. it's regressing all of a sudden


New member
SO i've had this hydanophora for about 8 months in my tanks.. since the first day i put it in it's ALWAYS been shaggy and happy and has grown a bunch! Its one of my favorite pieces since it's so big. However in the last couple weeks it's been regressing. The top branches are still shaggy and happy but the bottom half is completely closed up and the skin is starting to die at the very base and the first branch is getting worse!

Params are
SG 1.025
Temp 78.1
alk 9.2
cal 420
mag 1250
ph 7.9-8.3
ammonia 0
nitrites 0
nitrates 5
pho 0.25 maybe

I did add 2 small colonies about a month ago that came right from a shipper to LFS then to my house same day. The next day they were RTN and in 2 days all skin was gone and they were dead. Not sure if that had anything to do with it.

I dipped the hydanophora in revive for a 15 minute bath then put back into it's spot a couple days ago but no change.. I've come out at night, i've starred at it for long times and can't see any pest, i see what i think could be bite marks but then i look harder and it looks just like the bumps the polyps come from. Nothing else i see on it at all.

sorry for the crappy pics i only have my phone to try to take pics

A. Grandis

New member
I would think that could be simply because of the lack of light, not reaching that part of the coral. Specially if there is not enough reflexion of light from the bottom substrate.
What you could try to do, specially if you've got LEDs running, is to add some T5s for a more uniform illumination. Or, if possible, change the position of the coral/rock to see if that helps.
You can tell on the second picture how dark that area is. If you have no sand, maybe would be a good idea to try to add some around that area.

No matter how much you play with chemistry/ temp and filtration, if the problem is light.
Hope that helps.



New member
well it's in the same spot it's always been. I am running LED's but it's never been an issue with this coral acting like this. Come of my other corals were acting like it was to much light on the sand so i did turn them down just a bit from 60% to 55% but i would think it should still be enough. i never play with the lights or change settings on them unless something is doing bad then i'll turn on acclimation mode. I do have sand in the tank but the hydanophora is about mid way up in the tank.