Help, Problem with my Duncan

[Klewis]

I've had this Duncan for several weeks now and it was looking great. About 4 days ago I noticed it wasn't opening up all the way and a black spot developed on it. We've been feeding it 3 - 4 times a week directly with mysis shrimp. The tank has been established for about 2 years, I do 5 gallon water changes with ro/di water and tropic marin salt every two weeks, and I'm using chemi-pure elite in the back chamber with rock rubble and filter floss. Any input would be appreciated. I'll post parameters in a few.

 

[Zoous]

Does not look like a duncan. Looks like a dendro.

 

[prattreef]

That's a Dendrophyllia not a Duncanopsammia. Looks like a necrotic area, normally I 'd say to cut it out, but that looks like a tricky spot. Not sure what to tell you. Maybe drop the Cherry Corals guys a note as they seem to deal with this species alot. Good luck.

 

[Klewis]

This is too funny, I just learned that from pic on Acro76 post for the dendro's. It came with a tank I picked up and I thought he told me it was a duncan. Thank you for the clarification.

 

[Acro76]

I'll wait on the parameters...but tissue recession or loss in a stony coral can be caused by:

1. High phosphate (try an keep it under .03)
2. Low alkalinity
3. Low magnesium
4. Infection/injury/predation

Check your TDS of you R/O water too... It often sneaks up on you. I just checked mine a few weeks ago... 42! Our incoming water is about 119. After the prefilters get changed, it is back to 0!

An excellent article on important reef tank water parameters:

http://www.reefkeeping.com/issues/2004-05/rhf/index.php

 

[Klewis]

Thank you Acro76 for the response and information.

 

[crox99]

How are the other corals in your tank doing? From the pics they don't seem happy. JMO

 

[Pinkheine]

Are sure it isn't taking a doodie? I know when some of our corals "relieve" themselves they will close up for a day or two sometimes more and then they open back up.

IDK, don't have a dendros myself but it kind of looks like it to me from the picture.

 

[Klewis]

How are the other corals in your tank doing? From the pics they don't seem happy. JMO

Everyone else is doing fine, I took the picture during a water change thats why they're all closed.

 

[Klewis]

Are sure it isn't taking a doodie? I know when some of our corals "relieve" themselves they will close up for a day or two sometimes more and then they open back up.

IDK, don't have a dendros myself but it kind of looks like it to me from the picture.

HeHehe, thats what I originally thought, but a 3 day poop still concerned me even for a coral.