Established Acan colony closed up, other adjacent Acans unaffected

[cdw79]

I came back from vacation on Sunday to find my prized Acan colony very shrunken up. I saw it this way the day before when I checked on my tank through my Wyze camera I keep focused on the tank. My reefing New Years' resolution is to worry less, so I let it be. Today it appears that the issue is continuing, so I feel like I need some advice.

The colony has been in this spot for a good 5-6 months or so, and has never not been incredibly puffy. It seems to be the only coral in my tank that's not happy. There are also two acan frags next to it (see the very unflattering pic below) that seem completely unaffected. The same story for other corals in my mixed reef, including Acros and Monti. The tank has been established for a year and a half and has been smooth sailing, bar some Apex issues that I'm dealing with (CA measurement seems to have something wrong with it). I really just can't seem to figure out what's up with it

Params:
Alk (Apex)- 8.7 (up from 8.0 last Tuesday before my Apex had issues. I believe this is accurate)
Ca (Hanna)- 442
Mg (Apex)- 1393
Nitrate (Hanna)- 5.4 ppm
Phosphate (Hanna)- .19

I've been working to get the phosphate down, but this current level is not a new development. My only guesses right now are that me dosing Nitrate last Tuesday afternoon before I left may somehow have put them off (though it was a small amount and not the first time either) or that somehow a leather frag that's been in the tank about 3-4 weeks is releasing toxins (though I am running carbon). Any ideas would be greatly appreciated!



EDIT: Just borrowed a friend's Hanna checker and Alk is coming back as 10.1, which is a huge surprise to me. I have no idea how long it has been this way, nor how quickly it may or may not have changed. Maybe this is the issue

 

[Hubert J. Farnsworth]

on the surface, it sounds like a local physical problem, like a pest or nipping fish. you have any dwarf angels or other "reef safe with caution" type fish?

 

[dwest]

Agree with above. Plus look for sweeper tentacles of adjacent corals at night.

 

[cdw79]

on the surface, it sounds like a local physical problem, like a pest or nipping fish. you have any dwarf angels or other "reef safe with caution" type fish?

No fish that would be risks. The only remotely new addition was a gramma that got out of QT but there shouldn't be an issue there I wouldn't think. It barely even goes to that side of the tank.

Agree with above. Plus look for sweeper tentacles of adjacent corals at night.

The closest coral to it with any stinging power would be some hammers, but they are at least 6-8 inches away. Nothing else remotely in range. I'm a bit at a loss

 

[Hubert J. Farnsworth]

I came back from vacation on Sunday to find my prized Acan colony very shrunken up. I saw it this way the day before when I checked on my tank through my Wyze camera I keep focused on the tank. My reefing New Years' resolution is to worry less, so I let it be. Today it appears that the issue is continuing, so I feel like I need some advice.

The colony has been in this spot for a good 5-6 months or so, and has never not been incredibly puffy. It seems to be the only coral in my tank that's not happy. There are also two acan frags next to it (see the very unflattering pic below) that seem completely unaffected. The same story for other corals in my mixed reef, including Acros and Monti. The tank has been established for a year and a half and has been smooth sailing, bar some Apex issues that I'm dealing with (CA measurement seems to have something wrong with it). I really just can't seem to figure out what's up with it

Params:
Alk (Apex)- 8.7 (up from 8.0 last Tuesday before my Apex had issues. I believe this is accurate)
Ca (Hanna)- 442
Mg (Apex)- 1393
Nitrate (Hanna)- 5.4 ppm
Phosphate (Hanna)- .19

I've been working to get the phosphate down, but this current level is not a new development. My only guesses right now are that me dosing Nitrate last Tuesday afternoon before I left may somehow have put them off (though it was a small amount and not the first time either) or that somehow a leather frag that's been in the tank about 3-4 weeks is releasing toxins (though I am running carbon). Any ideas would be greatly appreciated!



EDIT: Just borrowed a friend's Hanna checker and Alk is coming back as 10.1, which is a huge surprise to me. I have no idea how long it has been this way, nor how quickly it may or may not have changed. Maybe this is the issue

just saw your edit, which i didn't see before. 8.0 to 10.1 is a pretty big alk swing if that occurred in short ordered. but then again, it sounds those numbers are from 2 different testing sources so maybe not that much of a swing in actuality if there is a big difference in their calibrations/results.

that said, i think dwest had another good consideration. not sure myself, but i don't think 6 to 8 inches is totally out of the realm of possibility for euphyllia to sting. i would look closely at all the closest polyps to the hammers, just to see if you can find any signs of damage.

is the affected colony the oldest stony coral in the tank? if that's the case, perhaps something more long term like a trace element deficiency is at play and some more in depth testing might be helpful.