Montipora Tissue Loss - Coral warfare or potential alk swing?

[george9]

Hey all,
Curious to hear some thoughts on this. I have a monti cap showing a bit of tissue recession which I noticed about 2 days ago and has since stopped progressing. Unfortunately I am having a hard time trying to decide if this is caused by a slight alk swing I had that coincidentally begun last week or if it is due to the encrusting acro nearby (although they cannot even touch yet)

I went out of town on May 25 and left my alk at 8.2. I returned on 5/29 to my tank with an alk of 6.7ish despite regular dosing. I believe the reduced co2 in the home led to a quicker uptake of alk and caused the drop. As of 6/3, the Alk was back to 7.8 and I am holding it steady there for now.

5/25 - 8.2 dkh
5/26-5/28 - no alk data
5/29 (late night) - 6.7
5/30 - 7.1
5/31 - 7.5
6/1 -7.2
6/2 - 7.7
6/3 - 7.8
6/4 - 7.8

Other parameters:
Ca - 440
mg - 1400
po4 - .07 - .1 ppm
nitrate 5-10ppm

I raised the alk a bit too heavy handed I think although this is the only place I see signs of stress at the moment. I noticed shortly after the “spike” back to 7.8 that a bit of tissue was lost on one of my monti caps, but see no issue anywhere else. the damage coincides with the closest location to an encrusting acro although I’ve never seen any filaments at night from this acro that would reach the monti and their tissue doesn’t touch at all. This is what is making me question if the alk swing is the cause at all since an identical monti cap piece next to this one further from the acro shows no recession.

Can they fight even though there is a bit of separation between them? Or is it more likely the alk swing caused this? The shape of this piece is a little odd because I accidentally chipped a chunk off about 2 weeks ago, but the new healthy white growth ring is already evident on the outer edge.


Ruling out pests due to no wet additions for months and no issues until now.

Curious to hear any thoughts, thanks!!

 

[Dburr1014]

I would put money on the coral over the alk.

 

[george9]

I would put money on the coral over the alk.

That’s what I’m thinking but am kind of annoyed this also coincided with the only time in history my alk dropped below 7.5.
If this is the case the damage should be confined to the edge right near the coral and hopefully the monti will just keep growing outward like it is.

How do acros typically fight? I assumed they had to physically touch another coral or release filaments that hit another coral. I’ve kept a close eye on these guys and haven’t seen anything abnormal between them during night or daytime, it doesn’t even have polyps yet on the flesh closest to the monti.

 

[Dburr1014]

That’s what I’m thinking but am kind of annoyed this also coincided with the only time in history my alk dropped below 7.5.
If this is the case the damage should be confined to the edge right near the coral and hopefully the monti will just keep growing outward like it is.

How do acros typically fight? I assumed they had to physically touch another coral or release filaments that hit another coral. I’ve kept a close eye on these guys and haven’t seen anything abnormal between them during night or daytime, it doesn’t even have polyps yet on the flesh closest to the monti.

If it was the alk, I would think it would have damage in other spots as well.
Acros are not so easy. Some do have to touch, some close contact.
In your case it is odd. It could be a growth spurt and the flesh will catch up. Just the white tip from the skeleton.

 

[george9]

If it was the alk, I would think it would have damage in other spots as well.
Acros are not so easy. Some do have to touch, some close contact.
In your case it is odd. It could be a growth spurt and the flesh will catch up. Just the white tip from the skeleton.

Interesting nonetheless. In any case, will keep the corals as they are for now and observe. I've read of montis getting stung and simply begin growing up and over to fight back... time will tell!

 

[Hurricane Aquatics]

I'm a bit late to this discussion, but that doesn't look like STN to me, it looks like you've had something munching on it. What fish or inverts do you have?

 

[george9]

I'm a bit late to this discussion, but that doesn't look like STN to me, it looks like you've had something munching on it. What fish or inverts do you have?

I just had clownfish and a Royal Gramma in the tank at the time. At this point, the tissue has 95% returned and I am thinking it actually was the alk drop that caused this. If this were warfare or munching, I'd think it would be continuing with the corals both in the same exact places still. I also have not added any new corals since the winter months, so the pest threat is pretty low IMO. Anyways, all is well with this cap now!

 

[X-37B]

I'm a bit late to this discussion, but that doesn't look like STN to me, it looks like you've had something munching on it. What fish or inverts do you have?

Yea it may be nudibranch eating it. They can come in on eggs and dont show up for months.

 

[Swiss Frag Reefer]

I would not be to concerned or changing anything. It is just sometimes how it goes. To the ALK swing theory, I had already multiple times when I measured my ALK was all the way down to 5dkh (due to growth and more consumption) from around 8-9dkh and never see anything really upset.

Your tank looks also on the newer side, so just let it go for now...

 

[george9]

Yeah definitely won’t be changing anything - especially since it is quickly recovering. The tank is just under 2 years old at this point.

I just think it’s highly suspect that this damage showed up the only time the alk has ever dropped from the proper range. Now that it has returned to near 8dkh the damage is quickly disappearing with no new damage since my original post almost 3weeks ago. Nudibranch damage wouldn’t magically stop once my alkalinity was raised, I’d think they would cause continuous damage?