Rapid Tissue Necrosis (RTN)

[IndyReefMan]

I just went thru a nasty episode of RTN. I've had the reef tank set-up for almost a year and never had any problems whatsoever. Water Parameters were just fine.

Ammonia- 0
Nitrite- 0
Nitrate- 2
pH- 8.2
SG- 1.025
Ca- 430
Alk- 3.5
PO4- .03
Temp- 80F

I lost almost all of my SPS corals and a few LPS corals. I did several large water changes and started changing the carbon every day (I usually change it once per week). Thankfully, this saved most of my corals and things seem to have stabilized. I haven't lost any more corals. I dose regularly with B-Ionic 2-part supplement and that is it. I rely on 10 percent weekly water changes to replace all other trace elements. However, upon the advice of my LFS, I have recently (after the RTN episode) started weekly dosings of Lugols solution (3 drops per week).

I wanted to start this thread to get other opinions on the causes and effects of RTN... I don't want to ever have to go thru that again! Anyone else out there dealt with RTN before? Any idea(s) what may have caused it? How did you deal with it? How long did it take your tank to recover?

Any opinions, ideas or theories would be greatly appreciated. Let's keep this thread full of great ideas so that we can all work together to take better care of our salt-water friends.

 

[IndyReefMan]

Bump.

 

[MT79]

I just went thru a nasty episode of RTN. I've had the reef tank set-up for almost a year and never had any problems whatsoever. Water Parameters were just fine.

So you have no idea what caused it? How long did it take to happen? Had you added anything, coral, etc., to the tank recently?

I have recently (after the RTN episode) started weekly dosings of Lugols solution (3 drops per week).

Can you explain why?

300W 20,000K MH,

What brand and ballast/lamp type? I've never heard of a 300w. Did you recently upgrade to MH?
BTW, I'm asking questions out of curiosity, at this point I've not yet experienced this(knocking wood and crossed my fingers!) so I doubt I could offer much advice/insight.

 

[Brenden]

I had 3 stars die with RTN within 10 days after introducing them to the tank but the package they were shipped in was left in full sun by UPS. All other stars in my tank are fine. Did you have a large temp change anytime recently.

 

[IndyReefMan]

So you have no idea what caused it? How long did it take to happen? Had you added anything, coral, etc., to the tank recently?

I went on vacation for five days and when I returned, it had begun. The only thing that happened while I was gone is a Mandarin died. I pulled his body out as soon as I saw it. Of course, I immediately thought that an ammonia spike initiated the episode but several AA members didn't think that this could have caused it (reference my thread posted two weeks ago entitled HELP! Corals Bleaching). Steve-S and several other members were assisting me. Within a few days, I had lost most of my SPS and a couple of LPS. There had been no new additions to the tank for at least 6 weeks.

Can you explain why?

I had not been dosing Iodine before the RTN episode. I saw several AA postings re: Lugols additions after searching it on this site. My LFS initially recommended it so I thought I'd check out what othet AA members had to say about it.

What brand and ballast/lamp type? I've never heard of a 300w. Did you recently upgrade to MH? MH

Actually, the 300W indicated total system MH wattage. I have (2) 150W 20,000K lamps. The bulbs are approx 6 months old. The PC bulbs are approximately 10 months old.

You're fortunate not to have experienced this yet... When it happens, it happens FAST. When you get a chance, check out that other thread that I referred to. Let me know if you have any ideas of what could have caused it.

 

[MT79]

I had 3 stars die with RTN

Pertaining to stony corals RTN, as it is called, is a much different situation. In stars it is usually relatively easy to pin point the cause-acclimation, water quality, etc. Basically- similar symptom descriptions, but totally different events.

 

[IndyReefMan]

Did you have a large temp change anytime recently.

Not that I'm aware of. The tank is in my basement and it is always very cool down there. Even in the Summer and the MH blazing away, the temp never goes higher than 81 degrees. I have a heater set at 80 degrees and that is where it stays.

 

[MT79]

I went on vacation for five days and when I returned, it had begun. The only thing that happened while I was gone is a Mandarin died.

Alright, now I remember the original thread. So it was not "out of the blue" so to speak. Something died, and you were not there to monitor the tank-water and animals. Although some dismissed this, I don't think it was all purely coincidental.... Having said that who knows though. Edit-maybe that slime coat that protects mandarins from infections etc. quickly fouls the tank when they die-especially after a day or two..?

dosing Iodine before the RTN episode. My LFS initially recommended it so I thought I'd check out what othet AA members had to say about it.

I personally would not use it unless I was regularly testing for it. I think NSW has approx. .06 meg/l(someone correct me if I'm wrong) of iodine. I've read iodine is lethal at even slightly elevated levels so be cautious.

When it happens, it happens FAST

So I've heard. Some say if it takes longer than 12-24 hrs it is not RTN b/c RTN happens so fast.

 

[IndyReefMan]

Alright, now I remember the original thread. So it was not "out of the blue" so to speak. Something died, and you were not there to monitor the tank-water and animals. Although some dismissed this, I don't think it was all purely coincidental.... Having said that who knows though.

Yes... others did dismiss it. On the other hand, I don't see anything else that could have caused it. That's why I started this new thread-- to obtain opinions and recommendations from other AA members who have experienced RTN as well.

I personally would not use it unless I was regularly testing for it. I think NSW has approx. .06 meg/l(someone correct me if I'm wrong) of iodine. I've read iodine is lethal at even slightly elevated levels so be cautious.

Yes, that's why I'm only dosing half the recommended dosage. I just started using it last week and I have ordered a test kit. I've done a lot of reading on this hobby over the years and I have read time and time again of the benefits of Lugols.

 

[MT79]

I've done a lot of reading on this hobby over the years and I have read time and time again of the benefits of Lugols.

I've recently read, since the "trend" toward keeping as close to NSW levels as possible, that "dosing" is becoming unpopular among some b/c it causes unnatural growth rates and patterns(I've never dosed anything but Ca/Alk). Although natural growth patterns would be extremely difficult to replicate in an aquarium w/ a stationary lighting system anyway... I'm getting off track lol. I would like to know how lugols provides benefits? Lack of water changes? Is your salt mix lacking in Iodine? High consumption? Any links/ articles?

 

[IndyReefMan]

I would like to know how lugols provides benefits? Lack of water changes? Is your salt mix lacking in Iodine? High consumption? Any links/ articles?

The thread that I saw is on this website. It is called "Iodine Question". Check it out and let me know what you think. PM if you could, I would like to try to keep this thread on the topic of RTN.

In the meantime has anyone else experienced any episodes of RTN? If so, were you ever able to determine what may have caused it? I am very interested in learning more about this... I would like to do what ever I can to prevent this from happening again.