Duncan Wont Open
 

Hi, I've had a duncan in my tank for about 6 weeks or so. For the past 10 days or so it won't fully open. Not sure what's going on. No new additions, none of the inverts are bothering it. It sometimes completely retracts and other times opens up as seen in the photo, but hasn't been fully open in 10 days. Tank Parameters Monia, Nitrate, Nitrite all zero. Temp 78-80. No changes in lighting sched. Most recent Triton here https://www.triton-lab.de/en/showroo...icp-oes/60827/

Anyone have any ideas on how I can get this guy open again

What fish do you keep?

What is the alk and salinity?

Nitrate of zero isn't necessarily good. How are you testing for that?

Yeah, I've noticed mine is really touchy about salinity. I'd double-check that.

I've also noticed that my duncan does go through a 2-3 week phase of being shy for whatever reason, but then comes out again in full with seemingly no change.

You say "currently cycling" so how old is this tank?
If your tank is not fully cycled and all parameters are not on point and stable, this coral has difficulty.
Near I see either a hammer, (which can sting lightly) or a torch (which can pack a huge sting) I can't tell from the pics.
Do you feed it? They love to grab Mysis.
I can't read the test, can you post all 8 parameters and number of weeks, months they have been stable?

Lack of stability and/or out of range is the number one reason for retraction.
10 days is too long...

Just adapting to the tank and lights. Maybe run carbon, try to feed, and relax.

Open a Little More Today
 

Hi.
I've updated my signature with little more info. System has been up about 5 months Salinity is 1.024-1.025. I use ATO to maintain stability. Alkalinity is 7.4 and monitoring almost daily since I just started Triton dosing. I know zero nitrate isn't ideal, and I'll try to address that in the future (The duncan closed BEFORE I started Triton dosing and my nitrates have been at zero since mid-July). I've been feeding about 2x a week with frozen mysis up until last week. I attempted to feed with Reef Roids last week but since it's been closed, I've seen no feeding response at all. The hammer and torch aren't in the duncan vicinity.
According to last Triton test (on 10/5)

Na 10681 mg/l
Ca 481 mg/l (since tested at 420ppm via API test)
Mg 1446 mg/l
K 420 mg/l
Br 53 mg/l
what are the other for "the big 8"?

The duncan looked a little better this morning. This is about the most open I've seen in the last 11 days or so. https://photos.app.goo.gl/GHS9Zqhetyr8EJhH8

In my experience Duncans are pretty tough. I have one that opens and closes as it pleases but over the past 6 months or so has gained 8-10 heads. I wouldn't worry about it unless it sucks itself in and stays like that for weeks. Otherwise they sometimes shrink to poop (you will see the brown stuff coming out of their mouths) or just because. I also have T5 lights and went I tried LED out for a few it was not happy. I put back on my T5's and it's good as new.:thumbsup:

Temp, salinity, PH, Alk, Ca, Mg, Nitrate, Phosphate.
Sometimes, iodide for leathers, shrimps and gorgonians
Sometimes strontium for clams....

I thought the Alk was a bit low at 7.4
I use 8.0-9.0

Yup, some trace nitrate and phosphate for corals to consume....

pH is 8.25-8.35
Iodine 0 µg/l
Strontium 7.525 mg/l
I'm having a little algae problem now, so I'm going to hold off on dosing any nitrate for now to avoid a supercharge of algae in my display

At 5-6 months, totally normal and expected.
Weekly WC, maintain chemistry in the ranges, strive for stability, this over the long term will both take care of the algae and provide the necessary stability for corals.

Splitting heads?
 

Well, this guy still won't open all the way. Sometimes (mostly at night) it completely retracts. Never opens up more than about this. Is it possible it's splitting more heads? It looks like there are a few little baby tiny heads at the top. Alk is up to 7.8 now. Calcium is down to 420-440 (according to API test) Haven't done another Triton test yet, but I assume all other parameters are the same.
https://photos.app.goo.gl/MyjLqr3b5RXcj4fX8

I bet someone is picking on him, they are sensitive to being messed with. I had to remove my file fish after the duncan was closed for a week. Once I put him in the sump the Duncan opened again. At least he's looking better then he did a few weeks ago.

Never seen anything bother it. The clowns seemed to try to host in it at night, but they've now taken to staying in the 2 back corners right at the surface at night (very weird). The skunk cleaner shrimp would occasionally walk over it, but never seemed to do any harm. Even with this the Duncans would be pretty much fully open for about 6 weeks or so...

Mine do better when spot feed a couple times a week. If closed up try feeding daily for a while if they will eat.

Did you change your lighting? I had one just about die when I turned up lights. I believe they do better in lower light.

My Duncan colony didn’t open for 3 to 4 months in my 110g mix reef tank but would open up in my 29g. Then after another 2 or 3 months I place it back in the 110g n now it fully opens up. If it open it only open very little. I still don’t know the reason. It did not die or loose it’s color. I didn’t change anything that I could remember.

I fragged my colony n place the frag in my 29g cube, that’s how I found out it opens fully in the 29g bio cube. Check your salinity maybe it’s too high.

How is the flow? My Duncan’s only like to open wide on lower flow spots.


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In my 110g I don’t think flow makes a different, my colony sits about 8 inches from the wavemaker, my smaller frag (about 10 heads) gets very little flow.

Good to know. This Duncans below only open about halfway if I turn the Jebao PP-4 in my tank up to 3 of 8 intensity in my Biocube 32, and the flow is off the glass.

https://uploads.tapatalk-cdn.com/201...326462d5c1.jpg


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Nice looking Duncans.

Yup, look well extended to me.

Nope. Used same light intensity. Flow is also the same as previous. They were open for about 6 weeks maybe but haven't fully extended in a month or so now :-(

Flow is also the same as previous. I'd say "medium" slightly indirect. I use a reverse pulse wave pattern (left on/right off then vice versa) and when the flow is "on" it's just enough to wave the polyps in the flow(when they were open). They were open for about 6 weeks maybe but haven't fully extended in a month or so now :-( I'll try reducing flow and see what happens

salinity has been stable at 1.0245-1.0250 for 6 months