Rapid Tissue Necrosis?

[sTefaniA]

I have never heard about this Rapid Tissue Necrosis thing. But I have been losing corals and RTN is what comes closest to it. Parameters have always been good, but still, corals are dying. Only sps, nothing else. Hammers, acans, clams, etc are doing well. Most sps are also fine, but then I will loose a coral that looks okay. White spots appear and sometimes it is dead within the day. Completely white. Sometimes it stops and the coral grows back. Usually it starts to go white on the foot, and then spreads to the branches.

untill there is nothing left

So please, if anyone can tell me this is RTN, because I don't know what is wrong so if I know, I can do something about it.


parameters:

no3 0-2
po4 0,003
ca 450
mag 1130
kh 8,4
ph 7,9 - 8,1
temp 24 °C

450g tank, 1730 watts of light hqi + t5

 

[Jfannin]

Don't have an answer for yah but I'm interested. So free bump

 

[James404]

I would dip that coral in Revive or CoralRx, it looks like possible AEFW.

 

[sTefaniA]

Not AEFW, I have showed one of the corals to a lfs and he checked it too. Dips also show nothing, I have tropic marin pro coral cure.
But, if it would be AEFW, shoudn't there be bite marks? Now the coral tissue just falls off, melts away sometimes in a matter of hours.

 

[James404]

Not AEFW, I have showed one of the corals to a lfs and he checked it too. Dips also show nothing, I have tropic marin pro coral cure.
But, if it would be AEFW, shoudn't there be bite marks? Now the coral tissue just falls off, melts away sometimes in a matter of hours.

To me in picture #2 there looks like possible bite marks. You are right there is definitely tissue necrosis, which can be caused by the AEFW. How fast is this occuring? Looks more like STN to me, RTN that whole coral would be white in a day.

 

[BowieReefer84]

Your Mag is kinda low, but don't think that would cause this. How do you control Alk? I had a swing in my Alk and had this issue. Not that the number isn't ok, but a sudden drop from 9.x to 7.x can have an impact. If you Alk has been constant at 8.4 then ignore this possibility.

What is your flow like? 450gal is HUGE to me, and would require a LOT of flow for sps.

If it takes the coral over a day or two to turn white I would say it is STN rather than RTN.

 

[sTefaniA]

To me in picture #2 there looks like possible bite marks. You are right there is definitely tissue necrosis, which can be caused by the AEFW. How fast is this occuring? Looks more like STN to me, RTN that whole coral would be white in a day.

It depends, I have fragged this one several times but some corals are fine in the morning and dead in the afternoon. Sometimes it stops and grows back. This was a very big coral, more than 10 inches high.

 

[sTefaniA]

Your Mag is kinda low, but don't think that would cause this. How do you control Alk? I had a swing in my Alk and had this issue. Not that the number isn't ok, but a sudden drop from 9.x to 7.x can have an impact. If you Alk has been constant at 8.4 then ignore this possibility.

What is your flow like? 450gal is HUGE to me, and would require a LOT of flow for sps.

If it takes the coral over a day or two to turn white I would say it is STN rather than RTN.

I use coral shop tests.
I have 2 vortech mp60 and 1 vortech mp40, and 1 ATB 4000g that pumps the water in from my sump.

 

[BowieReefer84]

Well flow is NOT the issue. Nice pumps!

 

[ChicagoReefOne]

It could be both RTN and STN events, either subsequently or simultaneously, I would imagine that that's entirely possible and from what you describe it seems like it could be happening as some piece die within a day and some recover.

I've never (knocking on wood) had AEFW but from what I see, I don't think it's that.

I had STN events when I had high dissolved organic content. What's your NO3 unit? ppm? Not sure what quantity 0-2 is. What's your skimmer?

 

[James404]

The reason I mention AEFW as a possibility is the circular marks in pic #2. I am currently dealing with them myself and I can tell you right now that they are pretty much impossible to see until you dip them. The eggs are easy to spot though. Either way a CoralRX or ReVive dip wouldn't hurt IMO.