Bald spot on Acro

USMA36 · Dec 27, 2023

I have had this Acropora in my tank since February. It has encrusted and grown well. Color seems fine and polyps are out. I believe it’s a Dan Aykroyd Acro. I’m pretty terrible at remembering names though. Anyway. As you can see from the picture it has a bald spot right in the middle. It’s been there for a couple of months now. It seems like it may be growing but at a very slow barely perceptible rate. Any ideas what would cause this. Alk 8.2 po3 .07.14 No4 15-20 temp 79 salinity 1.025 - 1.026. The bald spot looks like it has a slime coat around it kinda like what a green slimer does when annoyed or handled.

Troylee · Dec 27, 2023

Looks like a bill murray.. with that being said it looks like stn from the base up which is caused by alk swings and I’ve heard ph burn.. have either of those jumped or dropped?

USMA36 · Dec 27, 2023

No. Alk is always within .5

Troylee · Dec 27, 2023

Any direct flow blasting that area? Some times we’ll never know if it’s not the obvious

USMA36 · Dec 27, 2023

No direct flow. What would be the best way to stop that from spreading?

ryanjohn1 · Dec 27, 2023

Possibly stn

Troylee · Dec 27, 2023

USMA36 said:
No direct flow. What would be the best way to stop that from spreading?

I just leave it and hope the flesh grows back over it! Some times it does some times it don’t… if you can get it out people use super glue

DanyL · Dec 27, 2023

That is likely an STN or a burn, from the way it looks it might’ve been caused by stringing from another coral, I had acros fall down on chalices or mushrooms before and it looked very similar, although the burn signs appeared only after a day or two.

I would wait and see if it spreads out or not, if it spreads - cut whatever living tissue you can save and toss the rest.

If it stops, I recommend cutting a frag or 2 from the living tissue and gluing it over the skeleton, this would drastically speed up the healing process, although you could also wait for it to slowly grow back naturally.