Duncan coral not opening

Llorgon · Apr 30, 2020

Trying to figure out why my Duncan coral hasn't been opening up the last few days. It's been closed since Sunday afternoon a couple hours after my last water change.

Tank has been running since October with a house move in December. I got the Duncan as a one headed frag in late December. Since then it's been open and growing lots of new heads.

Tank params as of Monday are:
Salinity: 1.026
Temp: 78
pH: 8.2
Ammonia: 0
Nitrite: 0
Nitrate: 0.5
Phosphate: 0.018
Alkalinity: 9.5
Calcium: 435
Magnesium: 1470

Idoc · Apr 30, 2020

I bet it isn't happy with the low nitrates/phosphates...alkalinity is where they usually like it. I had a Duncan that wouldn't open for months besides small stubby tentacles. Once I raised my alkalinity to around 9-9.5 and then the no3/po4 was around 5-10ppm and 0.05-0.10ppm, respectively, and now the Duncan is really happy and growing like crazy.

Duncans are good canaries...they pick up water parameter changes and let you know when they are not happy!

Llorgon · Apr 30, 2020

Hmm that would make sense. It's the only coral in the tank that's not happy.

I did do a large water change on Sunday. 10g instead of usual 5g, vacuumed sand, cleaned filter socks, scrubbed rocks ect.

I have been battling gha and dosing vodka to help bring nutrients down. I still have a bunch of gha, but I can lower the vodka dose to try and raise nutrients a bit.

Llorgon · May 6, 2020

I brought my nutrients up a bit and still no change to the duncan.

Nitrate: 5
Phosphate: 0.028

Do I need to raise them more? My phosphates are at about average for my tank over the last few months.

This weekend is water change weekend so hopefully my normal 5 gallon change will make some improvement.

HB AL · May 7, 2020

Probably had to do with the water change and something changed enough in the chemistry of your water to cause it to close up. It will most likely open back up when ready.

El_Guapo13 · May 7, 2020

What do you use to do the tests?
What lights do you use, and how is the flow where it is at?

davescj · May 7, 2020

Have you tried spot feeding it even though closed? I had the same issue with mine. A friends suggested putting a piece of mystis on top of it as if I would fee it. I found that worked for me. Also, if the day is cloudy/fairy dark due to storms, the tank does not get morning light. Then sometimes the corals do not open even though the tank lights do come on.

fishguy242 · May 7, 2020

or just moving helps sometimes

jaxteller007 · May 7, 2020

We have a branching coral that goes through phases where it doesn't or barely opens and then without really changing anything it opens huge. I think like all live creatures they can be moody lol.

vetteguy53081 · May 7, 2020

Start with salinity. It is possible that you are getting a false reading and its' higher. Simply take a water sample to a trusted LFS and have them test for you. They aren't picky with PH unless its way off. Moderate light and water flow and you should be feeding them 1-2X per week.

jaxteller007 · May 7, 2020

I will say I am amazed at how hardy these guys are. We were told that when it was given to us as a 4 head frag, but I didn't really believe it at first. Since we've had it this is what its' been through.
Accidentally left white lights (Chinese black box leds) on for a whole weekend, thought I killed it.
It got knocked off it's rock while we were on vacation and half of it was buried in the sand.
Tank parameters were horrible and not stable.
Moved from 75G to 180G tank.
It's now probably 15 or more heads and just going and going. Only "scar" is from when it fell in the sand 2 or 3 of the smaller heads never seemed to have recovered.

Red Leader · May 7, 2020

I had a Duncan that retracted completely into its skeleton and I thought it died. Nothing else was affected in the tank. I left it in there and 2 weeks later there were these 11 tiny Duncans where there was 1 head. Weirdest thing.

Llorgon · May 7, 2020

HB AL said:
Probably had to do with the water change and something changed enough in the chemistry of your water to cause it to close up. It will most likely open back up when ready.

It must have been hopefully this weekends water change will get it back to being happy.

El_Guapo13 said:
What do you use to do the tests?
What lights do you use, and how is the flow where it is at?

Nitrate is red sea test kit and phosphate is Hanna.

Lights are radion xr-30, flow is probably medium ish. It has a decent wave to it when it was open.

davescj said:
Have you tried spot feeding it even though closed? I had the same issue with mine. A friends suggested putting a piece of mystis on top of it as if I would fee it. I found that worked for me. Also, if the day is cloudy/fairy dark due to storms, the tank does not get morning light. Then sometimes the corals do not open even though the tank lights do come on.

I have not. I will give it a try today. Weather has been all over the place since it closed up. Doesn't seem to make a difference.

fishguy242 said:
or just moving helps sometimes

If it still doesn't open after my water change then I will try moving it.

jaxteller007 said:
We have a branching coral that goes through phases where it doesn't or barely opens and then without really changing anything it opens huge. I think like all live creatures they can be moody lol.

I will hope it's just being moody since nothing has really changed in the tank.

vetteguy53081 said:
Start with salinity. It is possible that you are getting a false reading and its' higher. Simply take a water sample to a trusted LFS and have them test for you. They aren't picky with PH unless its way off. Moderate light and water flow and you should be feeding them 1-2X per week.

That could be. I did calibrate my refractometer before my last water change. Now if I can only find a place around me to test the water...

jaxteller007 said:
I will say I am amazed at how hardy these guys are. We were told that when it was given to us as a 4 head frag, but I didn't really believe it at first. Since we've had it this is what its' been through.
Accidentally left white lights (Chinese black box leds) on for a whole weekend, thought I killed it.
It got knocked off it's rock while we were on vacation and half of it was buried in the sand.
Tank parameters were horrible and not stable.
Moved from 75G to 180G tank.
It's now probably 15 or more heads and just going and going. Only "scar" is from when it fell in the sand 2 or 3 of the smaller heads never seemed to have recovered.

That's awesome! This one has been one of the better growers in my tank... at least until now.

Red Leader said:
I had a Duncan that retracted completely into its skeleton and I thought it died. Nothing else was affected in the tank. I left it in there and 2 weeks later there were these 11 tiny Duncans where there was 1 head. Weirdest thing.

Maybe it's just going to open up one day with a ton of new heads!

Aquavaj · May 7, 2020

I had to move mine 3 times before it was happy. Weird was that each spot was only 3-4 inches from each other due to space constraints in a nano.

Llorgon · May 7, 2020

I will try moving it tomorrow.

I tried feeding it tonight and it's slowly eating a LPS pellet. At least the biggest head is. Couldn't get it to stay on the smaller ones. So I will see where it's at tomorrow.

Llorgon · May 7, 2020

Aquavaj said:
I had to move mine 3 times before it was happy. Weird was that each spot was only 3-4 inches from each other due to space constraints in a nano.

Where in your tank was the Duncan happiest? I have mine on the sand and it's probably in medium ish flow.

Aquavaj · May 7, 2020

Llorgon said:
Where in your tank was the Duncan happiest? I have mine on the sand and it's probably in medium ish flow.

Down on the sand bed right outside of the overhang with low to medium flow.

jaxteller007 · May 8, 2020

Llorgon said:
I will try moving it tomorrow.

I tried feeding it tonight and it's slowly eating a LPS pellet. At least the biggest head is. Couldn't get it to stay on the smaller ones. So I will see where it's at tomorrow.

When I feed the fish frozen food (mysis shrimp mainly) ill use a turkey baster to squirt a bunch at the duncan. Every head tries to snatch and eat when I do it.

davescj · May 8, 2020

jaxteller007 said:
When I feed the fish frozen food (mysis shrimp mainly) ill use a turkey baster to squirt a bunch at the duncan. Every head tries to snatch and eat when I do it.

I use the giant tweezers that came with underwater aquatic plant kit. But the cleaner shrimp I have figured out it gives food, then the clowns did...and now I'm spot feeding every bleeding thing in the tank.

Llorgon · May 11, 2020

jaxteller007 said:
When I feed the fish frozen food (mysis shrimp mainly) ill use a turkey baster to squirt a bunch at the duncan. Every head tries to snatch and eat when I do it.

I usually do that as well, but with it completely closed up there is nothing out to grab things. So I put a pellet on the only head that it would rest on and it very slowly ate it.

davescj said:
I use the giant tweezers that came with underwater aquatic plant kit. But the cleaner shrimp I have figured out it gives food, then the clowns did...and now I'm spot feeding every bleeding thing in the tank.

I have the same problems with my clowns. They always try to steal the corals foods.

So I have done my regular 5 gal water change on Sunday, tried feeding the coral, tried moving the coral and no luck. I have also noticed that my 2 kenya trees aren't opening up either.

I've calibrated and rechecked salinity, done water change, added fresh carbon, re tested the water. Nothing seems off.

And to add to it the heater I use for my water mixing bucket broke sunday night! :mad: