NEED Help! Dying? Sun coral problem

[noobjelly]

I think my branching sun corals are dying. I kept those for almost 4 months, the polyps extension and encrusting part were getting better and better.

Picture 1: this picture was taken 10 days ago, they opened up nicely.

But for fews days ago (less than week), they start to refuse to open. Their polyps are barely extending but still accept target feeding.
For today, I noticed their tissues started to melt with circular pattern. i am not sure about this tissue necrosis or infection or something else.

Picture 2 and 3: my coral losing tissue at multiple spot and the base. Overall look like melting ice cream. Odor is strong like normal coral mucous.

I choose to do 5% iodine solution immersion (dosage; 5-10 drops/l) for 10 minutes and moved to other tank with higher flow.

Picture 4: remnants of immersion dip, mostly flatworms (I believed harmless species), amphipods and a bristle worm.

Picture 5: 30 mins after iodine dip in other tank, the polyps still can be open ?

For most of other corals is fine. The other sun corals in the tank still opened up and eating their food but don’t look fluffy as normal.
- 1 bubble coral
- 13 fat head dendros (some of them have slightly receding encrusting part of their base but still have great polyps extension)
- 3 colonies of different tubastraea
- 2 frags of duncan.
- pulsing xenia and heteroxenia
- kenya tree
- little sticks of blue polyps gorgonian
- a little frag of alcyoniun
- There are some gorgonian-like coral and gsp
- Green spotted puffer (onlyfish i have)

The recently added coral was tubastraea about 3 weeks ago (the middle-left colony in the pic1). They was starving and looking sick, so i get from former keeper for very low price. I have no idea they may associate with this problem or not (disease or parasites).

Picture 6: Recently added coral. Looking better compare to 10 days ago (pic1).

Picture 7,8 and 9: other suns/dendros still have good polyp extensions but i feel something doesn’t right as they were. Sorry for the algae and flatworm on the glass.

tank equipment, care and some parameters
- 10 gallons tank
- hob filter with biomedia (seachem matrix) and filter sponge pad (cleaning sponge pad every 2-3 days)
- hob filter with activated carbon, zeolite and filter resin (purigen)
- hob skimmers (cleaning collection cup every 2-3 days after doing water changes)
- 750gal./hr dc wavemaker
- 10-20% water changes every 2-3 days
- daily feeding 2 times per days : 1) broadcast feeding with frozen mysis shrimps when 2 hours before light-off 2) spot feed with frozen mixed (mussel, pods, artemia and powdered food) when 2 hours after light-off.
- Alkalinity 8.1 dKH (measured after light go off)
- salinity 35-36 ppt due to evaporation
- PO4 0.08 ppm (before feeding, yesterday)

I would apologize because i didn’t check for others parameters. these are all I have.

Does someone have any idea what can cause this sign or symptom to my sun coral ?

Are there any suggestions to treat my corals ?

please help me. I’m nervous about this so much. And thank you in advance.


I am sorry if there are any mistakes in my English skill.

 

[KrisReef]

I don't know what is happening here, but is your tank grounded? An electric leak may cause corals to suffer.

Otherwise, the circular holes are similar to flatworm bites, but they don't look like a typical flatworm infestation where the tissue attacks start nearer to the base of the coral.

I'm sorry, I don't have more specific diagnosis for your issues. Perhaps someone else will chime in?

(Your English is much better than mine. )

 

[noobjelly]

I don't know what is happening here, but is your tank grounded? An electric leak may cause corals to suffer.

Otherwise, the circular holes are similar to flatworm bites, but they don't look like a typical flatworm infestation where the tissue attacks start nearer to the base of the coral.

I'm sorry, I don't have more specific diagnosis for your issues. Perhaps someone else will chime in?

(Your English is much better than mine. )

Thank you for your reply.
My tank is not grounded. I will check for electrical leakages. I believed there are something or some parameters that aren’t right and I don’t measure them yet. For now, just be changed chemical media and trying to do more water change.