Leather Devils hand strange appearance

[cartoladota]

Hi everyone,

I'm new to the hobby and added my first corals about a week ago.
My leather coral was doing reasonably well at first, but around 3 days ago it closed up and started looking different. I haven't seen much improvement since then.
I initially thought it might just be shedding, because I noticed what looked like a loose/translucent film around the coral. However, after checking the back and the base more closely, I noticed a dark brown area around the lower part of the stalk, and there also seems to be a small hole/depression in that area.
The coral is still standing upright and seems structurally firm. I don't see large pieces of tissue falling off or obvious melting, but since I'm new to leather corals I'm not sure if what I'm seeing is normal shedding, irritation, or the beginning of tissue necrosis.

Parameters from yesterday (09/11/2026):
Temperature: 26.0 °C / 78.8 °F
Salinity: 1.026
pH: 8.10
Ammonia: 0 ppm
Nitrate (NO3): 12 ppm
Phosphate (PO4): 0.00 ppm
Alkalinity: 7.3 dKH
Calcium: 360 ppm
Magnesium: 1125 ppm

The tank is still quite young. I have recently started dosing All-For-Reef and I'm trying to bring Ca/Mg/alkalinity up gradually rather than making large corrections.
The coral is under moderate, indirect flow.
I'm attaching pictures from a few days ago and pictures from today. The newer pictures show the back/base of the coral and the brown area more clearly.
Does this look like normal leather shedding, or does the brown area/small hole look like tissue loss or necrosis?
Would you leave it alone and observe it for now, or would you recommend taking action?
Thanks in advance! I'm still learning, so any advice is appreciated.

 

[Mr. Mojo Rising]

It looks like something is boring into it, I would cut it above that hole and glue it down onto another rock. Put it into a low flow spot to heal for a week or two. But in general, leather corals like a good amount of random flow so once it heals move it up into more light and more flow. Thats just my 2 cents, good luck.

 

[cartoladota]

It looks like something is boring into it, I would cut it above that hole and glue it down onto another rock. Put it into a low flow spot to heal for a week or two. But in general, leather corals like a good amount of random flow so once it heals move it up into more light and more flow. Thats just my 2 cents, good luck.

Thanks for the reply. Anything that I can do to confirm before cutting? Also, how do I cut? Never did it before

 

[viceversabrd]

Looks like a ticked off coral to me, not sure about the hole could be due to suboptimal conditions. I think I would wait and see, I had a decent amount of coral casualties at the beginning. I feel like an aquarium needs to establish a nice microbiome (6 months up and running) for the coral(s) to thrive unless you're an old pro. I would probably dose phosphate (Neophos) your nitrates look okay, but my corals seem to really prefer a phosphate at minimum 0.05 up to 0.1+. My corals seem to wilt when phosphate gets near 0. Not sure if you're trying to bring up Ca/Mg/Alk with AFR but I dont think you can. If you read the instructions on AFR it says get your numbers where you want them with other products and maintain with AFR also AFR works through bacteria so in a new tank it may have a dampened effect.
So, for Mg I dose ESV Bionic Magnesium and for Ca/Alk I dosed TM Balling method part 1 and 2. Kinda sucked because I literally only used the Balling method part 1 and 2 a handful of times to get my numbers up and then have been coasting on AFR since. But now I have all this unused Balling method haha. I still does ESV Bionic Mg all the time but Im LPS/Torch heavy and try to keep Mg 1400+. All that being said I wouldn't worry about Ca/alk too much if you dont have any calciferous corals in there I don't think leathers really care. To accelerate microbiome I really like PNS deep cycle and PNS probio and then once you get some more corals in there PNS yellow sno for food.