STN? Bleaching? What is it, what do I do?

[k8eydid]

Hi all
I introduced this birdsnest 2 weeks ago and did not notice if the base showed signs of STN or bleaching when I purchased it, but in the past few days I see the white at the base and lack of polyps. Can anyone ID if this is STN or bleaching? I think if it was RTN, the coral would be dead already, I understand RTN can kill within days. I have also read other threads that SPS have recovered from these diseases. Any and all help is greatly appreciated and if I have to frag it, then I am prepared to do so.
Thanks!

 

[paintballer768]

What kind of flow and lighting do you have on the tank?

 

[k8eydid]

220 gal set up...
Lighting: 3 175W MH two 14K (sides) and one 10K (center), 4 65W PC actinic 420-460 with cooling fan in hood
Filtration: two overflows (rear corners) into the 30 gallon Sump containing sections for mechanical (sponge), protein skimmer, biological (bio balls), fuge (CC & LR)
Flow: Two quite one 4000HH 980 gph pumps through the sump, one directly back to the tank. The other through the Pentair 40W UV sterilizer and back to the tank, both with split directionals (upper back to front flow). One quiet one 9000 2328 GPH pump CLS powering 2 SCWDs split to 4 directional outputs (lower front to back flow)

 

[paintballer768]

Wow thats a lot of numbers there, Im not too good with the larger set ups. I can only imagine that it could be something flow related, as birdsnest's like lots of flow running in between the branches.

 

[nycbob]

what other sps do u hv? if it is bleaching or receding slowly, then it is reversible. factors such as water parameter arent right could cause bleaching. it could be anything from calcium level to alk. try checking ur parameters and let us know.

 

[gatorwpb]

Yeah you need to post water parameters. The flow sounds like it should be fine, unless it is sitting in a dead spot.
If its STN it can recover. RTN would be gone already. I lost a blue tort to RTN in about 18 hours.
Also, have you inspected it for a bad acro crab? Ive seen colonies damaged from the inside due to a bad crab eating the polyps.

 

[k8eydid]

what other sps do u hv?
I have no other SPS but have some LPS, Frogspawn, Favia, Acan, Brain - all are OK - and a few softies & shrooms
calcium level to alk. try checking ur parameters and let us know.
-
Salinity 1.024
Cal 340 - will be adding supplement to boost this
dKh 11 - Sorry no Alk test
pH 8.5 (@ 9:46 pm end of 5 hour MH daylight cycle) if it really matters

No3 (Trates) 0 to <5
No2 (Trites) 0
Temp 80
inspected it for a bad acro crab?
How big is an acro crab? This colony is not even 3" max in diameter, what am I looking for?
Thanks Bob & Gator!

 

[gatorwpb]

your parameters appear to be OK, dkH is alk. calc could be a little higher, but 340 is not going to cause STN or RTN.
An acro crab is usually very small, less than 1 cm (the bad one I had was that small) and usually fuzzy. They eat the polyps. I have 2 beneficial acro crabs and they usually have a thin black line connecting their eyes with a smooth body. They dont bother the coral at all.
If youve inspected the coral and dont see any crab, then something else is causing it.

 

[k8eydid]

Thanks Gator,
I have inspected and found no crabs, good or bad. The line of polyp recession does not appear to be getting any further up the branches as of today. I did move one of the overflow outputs to aim directly at the coral so it is getting as much flow as possible now. I will keep my eye on it and see what happens.

 

[nycbob]

who knows, maybe it was light shock.

 

[gatorwpb]

just make sure that the powerhead isnt giving it too much flow. they prefer strong indirect flow.
but if it isnt receding any more, then you should be good to go

 

[jpa0741]

I would get the calc raised and add more flow. If I am reading the numbers right you only have about 4400 gph of flow on a 220. That is only 20x turnover and IMO is not enough for sps. Also I am not sure how where it is placed but birdsnest likes to get blated with light.

 

[finland]

I agree with jpa, 20X turnover is not much for sps. I have a little over 50X in my sps tank. They love the flow. What is your phosphate level? From what I understand, high PO4 can cause problems. Also, how close is it too the softies? Sps and softies do not usually mix in close proximity. Just a few ideas...

 

[fattony]

If you see it progressing, frag the colony. You can also put superglue over the Necrosing tissue to try to stop it from going anyfurther.