Duncan Coral growing new heads? Does it close up?

[TacticalBacon]

My Duncan coral was opening and doing really good. About 20 mins after I placed it, it was open and it has stayed that way , closing at night and then opening in the mornings. Then all of a sudden, it has been randomly closing up and then opening half way, closing, opening a bit, closing, rinse repeat.

First video is from it being opened. Second video is what is doing now. It is opening more and more and then closing. Almost like it is stretching out and then resting.

I read on the interwebs that it does this when it is growing new heads.
Is this a true statement and does the images appear to be new Duncan Heads? Never seen them before, so I am not sure.

I have had the Duncan since 12/28.

I looked really closely, and I see some "heads" on the sides of the big one. The smaller ones open more often.

Tank Parameters, I am keeping a spreadsheet, so I can compare. I am also listing what was added, when, and where it was sourced.

Based on the RedSea LED50 Par guide they provide, I am keeping it in the 150-200ish PAR range (no actual PAR has been done but I am going to get it done to see how close the RedSea literature is. I have mine set up exactly how they have their LED50 setup.

Salinity	KH Alkalinity	PH	Phosphate	Calcium	Magnesium	Ammonia	No2 Nitrite	Nitrate	Temp
1.025​	163​	8.2​	0.2​	379​	1263​	0​	0.1​	10​	78​

 

[twentyleagues]

That does look like new heads.

 

[1112-425XL]

I have many corals that do exactly that. Duncan coral, Elegance coral, Lordhowensis coral, Acanthophyllia. They look great for weeks or months at a time, then randomly decide to stay closed or semi opened for days or weeks at a time. They always come out of it looking bigger and better.

 

[TacticalBacon]

I have many corals that do exactly that. Duncan coral, Elegance coral, Lordhowensis coral, Acanthophyllia. They look great for weeks or months at a time, then randomly decide to stay closed or semi opened for days or weeks at a time. They always come out of it looking bigger and better.

Appreciate the response and confirmation. You read so much and can read yourself into circles. Confirmation Bias is easy with the interwebs.

I am experiencing this for the first time and have no real experience to fall back on, so I appreciate the help.

 

[reefer2/19/24]

My Duncan coral was opening and doing really good. About 20 mins after I placed it, it was open and it has stayed that way , closing at night and then opening in the mornings. Then all of a sudden, it has been randomly closing up and then opening half way, closing, opening a bit, closing, rinse repeat.

First video is from it being opened. Second video is what is doing now. It is opening more and more and then closing. Almost like it is stretching out and then resting.

I read on the interwebs that it does this when it is growing new heads.
Is this a true statement and does the images appear to be new Duncan Heads? Never seen them before, so I am not sure.

I have had the Duncan since 12/28.

I looked really closely, and I see some "heads" on the sides of the big one. The smaller ones open more often.

Tank Parameters, I am keeping a spreadsheet, so I can compare. I am also listing what was added, when, and where it was sourced.

Based on the RedSea LED50 Par guide they provide, I am keeping it in the 150-200ish PAR range (no actual PAR has been done but I am going to get it done to see how close the RedSea literature is. I have mine set up exactly how they have their LED50 setup.

Salinity	KH Alkalinity	PH	Phosphate	Calcium	Magnesium	Ammonia	No2 Nitrite	Nitrate	Temp
1.025​	163​	8.2​	0.2​	379​	1263​	0​	0.1​	10​	78​

Mine were open a week and now closed. The largest head barely sticks a few tentacles out the other is closed and and the baby is kinda opening. Acclimation?

 

[TacticalBacon]

Mine were open a week and now closed. The largest head barely sticks a few tentacles out the other is closed and and the baby is kinda opening. Acclimation?

It could be. Mine did something similar. But I noticed around the neck it was growing new heads.

Does yours have new heads growing?
Have you tested your parameters?
Change your light schedule or flow?

 

[Shirak]

Mine were open a week and now closed. The largest head barely sticks a few tentacles out the other is closed and and the baby is kinda opening. Acclimation?

Start a new thread as you posted in another Duncan thread also. Photos of the coral in white lights, tank parameters etc. How long you have had it. The more details the better.

If it was open for a week and now closed it is unlikely acclimation.

 

[reefer2/19/24]

What do you think it could be?

 

[reefer2/19/24]

It could be. Mine did something similar. But I noticed around the neck it was growing new heads.

Does yours have new heads growing?
Have you tested your parameters?
Change your light schedule or flow?

I purchased at a frag swap and all seemed well with them. 2 larger heads and one small one. Just looked this morning and there's a neon we're closed sign.
Parameters tested on 2/1/25

ALK 7.0
PHOS 0.01
NITRATE 0.0
CALCIUM 589
MAGNESIUM 1150

Everything except Duncan's seem happy. Low dosing AFR 15 ML in a 100-gallon system nightly. Feeding a bit more to bring up NITRATE. Thinking about moving them to a darker spot but par is in that area about 120.

 

[NCsalt]

Alk low calcium high mag low. Getting mag higher can help with alk and calcium getting out of wack from each other.

 

[TacticalBacon]

I purchased at a frag swap and all seemed well with them. 2 larger heads and one small one. Just looked this morning and there's a neon we're closed sign.
Parameters tested on 2/1/25

ALK 7.0
PHOS 0.01
NITRATE 0.0
CALCIUM 589
MAGNESIUM 1150

Everything except Duncan's seem happy. Low dosing AFR 15 ML in a 100-gallon system nightly. Feeding a bit more to bring up NITRATE. Thinking about moving them to a darker spot but par is in that area about 120.

I am keeping my alk at 8-8.5 and working in my calcium.

Flow was a big challenge for me. Finding a spot where they get enough flow but not too much.

I placed mine between two rocks on the bed. I have a 43g cube with 2 Red Sea LED 50s.

I was in a panic when mine closed but it was they were growing new heads. They were that way for the better part of a week.

 

[Shirak]

I purchased at a frag swap and all seemed well with them. 2 larger heads and one small one. Just looked this morning and there's a neon we're closed sign.
Parameters tested on 2/1/25

ALK 7.0
PHOS 0.01
NITRATE 0.0
CALCIUM 589
MAGNESIUM 1150

Everything except Duncan's seem happy. Low dosing AFR 15 ML in a 100-gallon system nightly. Feeding a bit more to bring up NITRATE. Thinking about moving them to a darker spot but par is in that area about 120.

Start a new thread rather than hijacking this one. If you want to ask the OP about their situation and what they did to resolve it great but for your coral you should start a new thread.

As for your parameters. As mentioned Alk is on the low side and magnesium is on the low side. What's your salinity? Your nutrients are also effectively 0 which is bad.

Calcium at 589 with alk and magnesium where they are?? Sounds like a testing error or you are dosing calcium for some reason. If it is that actually that high it is not a problem for the corals. You most likely will get precipitation if you raise your alk, but that's about it.

Magnesium is also difficult to get a good test result with hobby test kits.

START A NEW THREAD. Post photos and additional information on light levels Salinity etc.

 

[reefer2/19/24]

Start a new thread rather than hijacking this one. If you want to ask the OP about their situation and what they did to resolve it great but for your coral you should start a new thread.

As for your parameters. As mentioned Alk is on the low side and magnesium is on the low side. What's your salinity? Your nutrients are also effectively 0 which is bad.

Calcium at 589 with alk and magnesium where they are?? Sounds like a testing error or you are dosing calcium for some reason. If it is that actually that high it is not a problem for the corals. You most likely will get precipitation if you raise your alk, but that's about it.

Magnesium is also difficult to get a good test result with hobby test kits.

START A NEW THREAD. Post photos and additional information on light levels Salinity etc.

Shirak, I appreciate you jumping in. If I knew how to start a new thread and add photos I would certainly do it. I'm 64 years old and I just don't know how? So I appreciate your time and help with this matter. And should you genuinely want to help myself and others who might not be as technically savvy as yourself please feel free to reach out to me. I would love to learn something new and cool.
Sincerely,
Earl Griffin

 

[Shirak]

Shirak, I appreciate you jumping in. If I knew how to start a new thread and add photos I would certainly do it. I'm 64 years old and I just don't know how? So I appreciate your time and help with this matter. And should you genuinely want to help myself and others who might not be as technically savvy as yourself please feel free to reach out to me. I would love to learn something new and cool.
Sincerely,
Earl Griffin

When you go to the general LPS forum, there is a blank box above the sticky posts. Click on that an you can input a title for a new thread. Will open up an area for you to type your post, add photos etc! Look forward to more details on your Duncan:)

 

[reefer2/19/24]

When you go to the general LPS forum, there is a blank box above the sticky posts. Click on that an you can input a title for a new thread. Will open up an area for you to type your post, add photos etc! Look forward to more details on your Duncan:)

Thank you for your time and help with me.

 

[Barb0713]

Appreciate the response and confirmation. You read so much and can read yourself into circles. Confirmation Bias is easy with the interwebs.

I am experiencing this for the first time and have no real experience to fall back on, so I appreciate the help.

This is my second round of addiction. I learned a lot the first stretch but, the information is endless. This site helped me through a lot and it continues today. Thanks everyone

 

[Barb0713]

Oh forgot to leave the comment lol. I have a ducan and it was doing good for a few days. Just closed up and it has 5 heads. One of them have 3 heads emerging all the way. It’s amazing to watch :)

 

[TacticalBacon]

Oh forgot to leave the comment lol. I have a ducan and it was doing good for a few days. Just closed up and it has 5 heads. One of them have 3 heads emerging all the way. It’s amazing to watch :)

Same, scared me to death. I was testing 2-3x’s a day. Went to the LFS and had them test.

Then got in here and by time I was calm it had sprouted a few more heads.
Now it’s just growing and flowing.

 

[Barb0713]

Same, scared me to death. I was testing 2-3x’s a day. Went to the LFS and had them test.

Then got in here and by time I was calm it had sprouted a few more heads.
Now it’s just growing and flowing.

Beautiful. I just attached mine to the rock today and it bounced back in an hour :) and multiple heads came really out over the next few hours. Picture is bad , coral is still a little upset lol but , the 4 new ones popped right out as soon as the faced the lights.