Goniopora dying, what's going wrong

[BadgersSong]

Another one's going down - my goniopora's shedding like crazy now. Had a similar issue with a toadstool a few months back and it didn't end well. I've tried dipping it with Coral RX but it's still shedding away. I've always used ginopower for feeding and it's always done great, but now it's like nothing's working. I've changed nothing in the system, did a water change thinking it might help, but no dice. Parameters all look normal:
Cal: 420, Alk: 7.7, Mag: 1320, Salinity: 1.026, PH: 8.12, PO4: 0.0, Nitrate: 0.02. Starting to lose hope - should I just throw in the towel or keep trying?

[talonix]

Honestly, I'm not optimistic about the outlook. I've been in a similar situation before, early on in my tank-keeping journey, and unfortunately lost a coral that was exhibiting similar symptoms. If you can find a way to rescue the still-healthy polyps, there's a chance it might recover, but I'm stumped as to what's causing this. Your parameters all seem to be in order - the one thing that jumps out at me is the ALK, which might be a tad low, but other than that, everything looks good.

[Fableon9]

How long have you had this goniopora? Is it around that 18-month mark, I'm just wondering if that could be a factor here.

[stardog]

Goniporas can be notoriously finicky, especially the green ones - they can bail on you at any time.

[brixo]

I'm a bit skeptical about your PO4 reading, is it genuinely undetectable or is that just the limit of your test kit? If it's dropped from a higher level to basically zero, that might be the issue - a tiny bit of PO4 and some nitrate are essential for the health of your photosynthetic corals like the goniopora.

[flynix]

I'd say it's likely infected, given the shedding you're describing. Unless you've got a suitable treatment, like an antibiotic, I'm afraid it might not make it.

[BadgersSong]

How long have you had this goniopora? Is it around that 18-month mark, I'm just wondering if that could be a factor here.

I think it's around that 18-month mark now, I'm wondering, is this some kind of common issue that happens around this time?

[Fableon9]

I've come across this issue before in a few threads on RC, seems like it's not uncommon. I recall reading about it, but can't find the links right now - I'll try searching again tonight to see if I can dig anything up.