Duncan decay

[mmusc1987]

Hey all!

I am running into a strange issue with my Duncan. Got him as a baby one head polyp 2 years ago and he has thrived and grown exponentially. A few days ago I noticed a few polyps didn’t look so hot and then another couple of days go by and it looks like he is starting to rot. My parameters are as follows. I use Hanna Checker for my testing.

Ammonia 0
Nitrites 0
Nitrates 8.3
Alk 5 dkh
Calcium 518
Phosphate 0.05
Specific Gravity 1.024

Please help. I have a few theories for potential causes but would like to hear your opinions.

All other corals (LPS and softies) doing well and growing

 

[mmusc1987]

Also please forgive the algae. It is due for a deep clean.

 

[Gumbies R Us]

What about alk? Any changes to lighting or flow? Any fish that could be bothering it?

 

[fishyjoes]

It's probably not the cause, but calcium of 518 seems pretty high

 

[vetteguy53081]

Hey all!

I am running into a strange issue with my Duncan. Got him as a baby one head polyp 2 years ago and he has thrived and grown exponentially. A few days ago I noticed a few polyps didn’t look so hot and then another couple of days go by and it looks like he is starting to rot. My parameters are completely appropriate. I use Hanna Checker for my testing.

Ammonia 0
Nitrites 0
Nitrates 8.3
Calcium 518
Phosphate 0.05
Specific Gravity 1.024

Please help. I have a few theories for potential causes but would like to hear your opinions.

All other corals (LPS and softies) doing well and growing

While calcium is high , it would have affected more than one head if this were the issue. Other causes can be:
Low alk
Low PH
Elevated temperature
* High Phosphates (one of my suspects)
Change in water flow
Change in salt

How are you checking nitrates?

 

[mmusc1987]

It's probably not the cause, but calcium of 518 seems pretty high

Actually you might be on to something. I neglected to test the alk the first time and I am glad the comment above requested the parameter.

My alk is 89.7 or 5dkh

In my experience if the alk is generally low then the calcium is pretty high. Hence 518.

would this be the cause of Duncan Decay though?

Would kalkwasser be the recommended solution for the fluctuations in the alk/calc?

 

[mmusc1987]

While calcium is high , it would have affected more than one head if this were the issue. Other causes can be:
Low alk
Low PH
Elevated temperature
* High Phosphates (one of my suspects)
Change in water flow
Change in salt

How are you checking nitrates?

Alk is low at 5dkh. I use a Hanna checker for the nitrates and that has resulted in an 8.3 twice.

 

[mmusc1987]

Alk is low at 5dkh. I use a Hanna checker for the nitrates and that has resulted in an 8.3 twice.

Would low alk cause decay on one head?

 

[vetteguy53081]

Would low alk cause decay on one head?

It can but generally more than one head. You must balance the alk and calcium as they work hand in hand. When I saw high, CA, it indicated a possibility of alk being low

 

[twentyleagues]

We know alk at 5 is low but I dont think that would effect only 1 or 2 heads. Try fixing that and see if it bounces back.

 

[MnFish1]

Would low alk cause decay on one head?

No one knows - but it could be an evolutionary adaptation to save the colony that some are sacrificed. Your alkalinity (assuming your test is correct).

 

[DanyL]

I agree, an imbalanced Alk/Ca can cause all sorts of problems.

One or two head dying from a colony may sometimes indicate a long lasting STN, or in other words - a long lasting stress on the coral, which may have been induced by more than one reason (fluctuations, change in flow/lighting, contamination, etc).

 

[mmusc1987]

I am pretty sure it was the brand new bucket of salt. I tested it before a water change with RODI water and the calcium level was at a 552. On my way to get another bucket of salt.
I was able to get the alk raised to a 7 but will probably have to do some frequent testing over the next week to get it stable.
Duncan is still not happy and looks like it is rotting but I will do a large water change with the new salt (after pre testing it) and give him a couple recoup days. Fingers crossed