Duncan Died Overnight

OdinCorals · May 1, 2019

Duncan coral suddenly closed up last evening, today I found it covered in like a slimy texture, I tried to blow the slime away but the Duncan disentigrated, there is little left of it. My question is why?

Duncan has been in tank for over a year, stable tank for over 19 months, params below, maybe necrosis, bacteria? I did not introduce any corals / live stock for the last 3 months and only buy from reputable LFS.

Tank is 23 gallon nano.
KH - 9
No3 - 5-10
Phosphates - 0
Salinity - 1.023
Temperature: 77-78
Good flow, AI prime light setup, dosing of CA, KH, MG, NOPOX daily via doser.
bi-weekly 5% water changes, mainly for nitrate export.

what could have happened? meh.

2 days ago photo:

today:

Mical · May 1, 2019

IMO you did nothing wrong, Duncans are in a league of their own. I've had some look great for months and do the same as yours. I have a couple right now that will close and shrink to nothing then days later new multiple heads. I concentrate my efforts on other growing corals and just observe the duncans. If anything on your parameters - I'ld "up" the salinity to 1.026 (slowly)

timrocks311 · May 1, 2019

I agree with the salinity being low, but besides that, I don't know what it is exactly. If you've had the Duncan for a year, I'm surprised it hasn't grown more. I've had my Duncan for almost a year now; bought it as one head and it must have 20 now. It's the size of a small fist.

OdinCorals · May 1, 2019

to be honest I was advised to lower salinity to lower a bit the KH and get more colors showing from the corals, which is true, but maybe the Duncan took a shock lol. thanks all.

DangerDave · May 1, 2019

I don't think it's dead, it just looks retracted in the photo. Give it time. I have few hundred Duncan heads. A couple months ago a small cluster died. It was basically gone overnight, nothing left. None of the others were effected. Sometimes it just happens and you'll never know why. Give it some time and see how it does.

Nburg's Reef · May 1, 2019

I agree on the sentiment that if you've had it over a year and it hasn't grown much, there is something wrong either with it or it's not liking your system. They should grow pretty rapidly. If you only have 1 or 2 polyps, it could have been stressed and finally succumbed to something, or maybe it ingested something like salt or alk precipitate. Those things can be like the phoenix, so I wouldn't discard it yet, it may come back.

OdinCorals · May 4, 2019

hey All, just an update.

I noticed today that one of my dosing pumps jammed, it might have been working on / off for the last week or so, it was dosing the KH, although I did test KH and it was in good ranges, it could have caused the death of the Duncan, like you all said the Duncan might have been already stressed and the sudden fluctuation in KH was the cherry on the cake.

thanks all. great community, keep it up.

amazongb · May 4, 2019

You didn't mention fish or other livestock in your tank. I had a flame angel that started nipping at a duncan more than a year after being in the tank together.. use a flashlight a night ..

OdinCorals · May 4, 2019

amazongb said:
You didn't mention fish or other livestock in your tank. I had a flame angel that started nipping at a duncan more than a year after being in the tank together.. use a flashlight a night ..

hm, I have 2 clowns, 3 chromis, 1 red fire shrimp, a lot of snails, some Bristle worms and a hermit crab... hmm hermit maybe, they are di**heads

amazongb · May 4, 2019

OdinCorals said:
hm, I have 2 clowns, 3 chromis, 1 red fire shrimp, a lot of snails, some Bristle worms and a hermit crab... hmm hermit maybe, they are di**heads

I've never owned a fire shrimp, but just read up a bit and it seems they can nip at corals. Again, try spending some time when the lights are out and maybe you'll discover the culprit. I've never had any other issues with duncans, they are pretty hardy..so my hunch is the shrimp.

tehmadreefer · May 4, 2019

OdinCorals said:
to be honest I was advised to lower salinity to lower a bit the KH and get more colors showing from the corals, which is true, but maybe the Duncan took a shock lol. thanks all.

Well, there's your problem.
Whomever told you low salinity is good deserves a facepalm. Also zero po4 is bad.

There are no studies that show low salinity increases coral coloration by lowering KH. That's just the wrong and lazy way of doing things.

OdinCorals · May 4, 2019

tehmadreefer said:
Well, there's your problem.
Whomever told you low salinity is good deserves a facepalm. Also zero po4 is bad.

There are no studies that show low salinity increases coral coloration by lowering KH. That's just the wrong and lazy way of doing things.

I did see more colors when reducing KH, the salinity might be what caused the shock, po4 is not exactly 0 but very low like 0.03

now I am just hoping there is not going to be a crash or something. I found a broken dosing pump so I might had messed up params for a while.