Help- Duncan coral suddenly not extended

[SelkieSam]

Hi! I have had this Duncan coral for almost a week and it has been doing well. I just checked my tank parameters this morning and made no adjustments today since everything was good. It was happy all day but when I just looked again it has no tendrils extended, mouth is open, and I see this weird part moving on the backside.
Literally maybe half an hour between looking perfect to looking like this. I am new to coral so forgive me if the part on the

back is normal growth or something. Just concerned with the sudden change in behavior being so dramatic

 

[afrokobe]

You should post your full parameters and tank specs as others will ask. are those rocks reef safe?

 

[SelkieSam]

You should post your full parameters and tank specs as others will ask. are those rocks reef safe?

Ph is ~8.2
Calcium ~ 460
Nitrates 20
Nitrites 0
Ammonia 0
Alkalinity 300ppm
Salinity 1.025

I have a live rock and live sand that I got from the fish store. The other small rocks are mostly ocean rocks that were rinsed and then sat for a few years in dry storage. They have been in the tank throughout the initial cycling and so on.
This is a 9gallon which finished cycling about a month ago and this is the first coral added.


I have a royal gramma and blue legged hermit crab that have been living in it. No other livestock aside from a candy cane coral which was placed at the same time as the Duncan.

Updated photos attached.

thanks!

 

[Mr. Mojo Rising]

what kind of light do you have? Can you show a full tank pic? It helps...

 

[IslandLifeReef]

How big is that Duncan? Based on the small rocks and shells along with the sand dollar, it looks like it is the size of a penny. It also seems to have something growing on the back of it, could be aiptasia, but doesn't really look like it.

 

[SelkieSam]

It is very small and only takes up maybe a quarter size when open.

 

[afrokobe]

Ph is ~8.2
Calcium ~ 460
Nitrates 20
Nitrites 0
Ammonia 0
Alkalinity 300ppm
Salinity 1.025

I have a live rock and live sand that I got from the fish store. The other small rocks are mostly ocean rocks that were rinsed and then sat for a few years in dry storage. They have been in the tank throughout the initial cycling and so on.
This is a 9gallon which finished cycling about a month ago and this is the first coral added.


I have a royal gramma and blue legged hermit crab that have been living in it. No other livestock aside from a candy cane coral which was placed at the same time as the Duncan.

Updated photos attached.

thanks!

Your parameters look ok, the only thing that is a concern is the 300 PPM of alk, which would equal almost 17 dKH. Nitrates are a little bit low outside of that for stuff like duncans.

 

[IslandLifeReef]

It is very small and only takes up maybe a quarter size when open.

Have you ever noticed your blue leg hermit around it. With it being so small, it could easily be irritated by the hermit, or the hermit could be testing it for food.

 

[SelkieSam]

what kind of light do you have? Can you show a full tank pic? It helps...

It is a 9 gallon fluval tank and the lights are in the lid. I rotate different colors and have it off at night. Some natural light in the room during the day as well.

 

[SelkieSam]

Have you ever noticed your blue leg hermit around it. With it being so small, it could easily be irritated by the hermit, or the hermit could be testing it for food.

Hmm I have not noticed that behavior but I will keep an eye on the crab to see

 

[Seymo44]

I have two Duncan colonies that are around 20-30 polyps each. Both, when young, would get ticked and close up for days.

They are generally a hardy coral and are typically easy to care for.

How long has your Duncan been this way?
Is it new to your tank?

 

[Seymo44]

How big is that Duncan? Based on the small rocks and shells along with the sand dollar, it looks like it is the size of a penny. It also seems to have something growing on the back of it, could be aiptasia, but doesn't really look like it.

I’m with you there, definitely looks like an aiptasia.

Perhaps the OP should pull the coral and smother the aiptasia with superglue.

 

[SelkieSam]

I have two Duncan colonies that are around 20-30 polyps each. Both, when young, would get ticked and close up for days.

They are generally a hardy coral and are typically easy to care for.

How long has your Duncan been this way?
Is it new to your tank?

It has only been this way for a little over an hour. It was nice and open and eating earlier today. I added it to the tank about 4 days ago.

 

[Rmckoy]

Duncan’s are a weird coral .
many say they are almost bullet proof but it’s one of the corals I can’t keep alive in my system .

are you dosing anything to the tank ?
There really is nothing to explain the high Alk or testing error .
confirm these values with another kit before taking action to correct it .
I’d do a few water changes to lower it slowly .
What salt are you using ?
What test kits are you using ?

 

[SelkieSam]

I’m with you there, definitely looks like an aiptasia.

Perhaps the OP should pull the coral and smother the aiptasia with superglue.

Duncan’s are a weird coral .
many say they are almost bullet proof but it’s one of the corals I can’t keep alive in my system .

are you dosing anything to the tank ?
There really is nothing to explain the high Alk or testing error .
confirm these values with another kit before taking action to correct it .
I’d do a few water changes to lower it slowly .
What salt are you using ?
What test kits are you using ?

I have reef crystals salt and have not been dosing anything other than seachem prime and stability with water changes. As needed I have used a small amount of seachem reef buffer to raise the ph, but only a couple of times as it is usually high enough just from the reef crystals. The test strips are the tetra strips, and I also use the api nitrate, nitrite, ph, and calcium test kits separately.
The alk test is on the strip so I am unsure how precise it is.

 

[radfly]

Duncan is a good indicator coral, mine detects low salinity and low calcium. It also closes for two days when making another head.

 

[SelkieSam]

I’m with you there, definitely looks like an aiptasia.

Perhaps the OP should pull the coral and smother the aiptasia with superglue.

Is aiptasia something that is a sign of a bad fish store? Should I avoid shopping there in the future, or is it just unavoidable sometimes?

I appreciate any advice on how to eradicate it

 

[Seymo44]

I really hate to be the bearer of bad news, but API test kits are virtually useless. The tank seems pretty small, so additives are probably not needed with regular water changes.

 

[afrokobe]

I have reef crystals salt and have not been dosing anything other than seachem prime and stability with water changes. As needed I have used a small amount of seachem reef buffer to raise the ph, but only a couple of times as it is usually high enough just from the reef crystals. The test strips are the tetra strips, and I also use the api nitrate, nitrite, ph, and calcium test kits separately.
The alk test is on the strip so I am unsure how precise it is.

this is a bit of concern that you are using prime for water changes. Are you using rodi water? or tap with prime?

 

[SelkieSam]

I really hate to be the bearer of bad news, but API test kits are virtually useless. The tank seems pretty small, so additives are probably not needed with regular water changes.

Is there a good set of tests you recommend?