Why Do SPS RTN?

[Joe Knows Reefs]

So, I recently had a birdsnest colony RTN overnight. No apparent causes. The colony started out as a 1.5" frag and grew bigger than a grapefruit and then bam...it melted away. All other SPS in the tank looked fine - perfect color and PE. All params were in check and no swings. The next day a colony beside of it started to RTN. I cut off the branch that was melting and the rest of the colony was fine. A monti colony that was nearby melted 2 days later. And then, random frags that had been healed for 2, 3, or even 4 weeks started going. In all I lost the birdsnest, the monti colony, and 3 or 4 frags. Everything else fared well and is still kicking like nothing ever happened.

I know RTN has been questioned for a long time and can be contributed to Alk and/or pH swings. I had neither. I have also read theories on bacterial infections causing the problems.

Any thoughts/ideas?

 

[AcroholicReefer]

I can speculate but I don't have a definite answer. One thing I know for sure is that it really sucks and I have had them go one at a time. When they do, kick in the water changes full blast and eventually you get ahead of it. I also wonder if dosing Hydrogen Peroxide will stop the pathogen from spreading, if it is a pathogen that is causing the RTN and not parameter swings.

 

[Aquaph8]

Im sure there are many reasons. Alk/PH swings would be on the top of my list though.

 

[Joe Knows Reefs]

I can speculate but I don't have a definite answer. One thing I know for sure is that it really sucks and I have had them go one at a time. When they do, kick in the water changes full blast and eventually you get ahead of it. I also wonder if dosing Hydrogen Peroxide will stop the pathogen from spreading, if it is a pathogen that is causing the RTN and not parameter swings.

I've wondered the same thing about peroxide but am unsure how to dose it. The more I look at my situation it really had to be contributed to a pathogen of some sort

Has anyone else had this experience? Where it travels from one colony to the next until it is stopped?

 

[Luisra]

Ammonia spikes, sudden increases or decreases in Ca and/or Alk; sometimes it may be due to lack of flow.

 

[Dave3112]

I wish I knew too!! I had this happen last year to me. it lasted about 2 months or so and only affected my large colonies. None of the frags. But mine didn't affect my monti caps just the digis. Then as sudden as it started it stopped!!! I had NO PH, ALK, CA or Sg swings AT ALL!!! I checked everything twice a week and with new test kits. I even sent some to my LFS to test and they had the same numbers as I did. I use Elos test kits and they use Hanna meters and salifert. It is still a mystery to me as to what happened. Good luck man. I am going to follow along and see what responses people give, other than Alk,PH swings. Which it seems that NEITHER of had.

 

[islander84]

the number one killer of all coral that noone has mentioned is temp.....being that it has been getting cooler in the evenings has your temp had a swing that could have caused this? do you have any electricity leaking into your water column....could also be bugs...i have seen tanks with aefw cause entire colonies to rtn overnight......

 

[islander84]

what is your dkh just out of curiosity and how are you checking it?

 

[Joe Knows Reefs]

Ammonia spikes, sudden increases or decreases in Ca and/or Alk; sometimes it may be due to lack of flow.

None of those were the case in my situation...

I wish I knew too!! I had this happen last year to me. it lasted about 2 months or so and only affected my large colonies. None of the frags. But mine didn't affect my monti caps just the digis. Then as sudden as it started it stopped!!! I had NO PH, ALK, CA or Sg swings AT ALL!!! I checked everything twice a week and with new test kits. I even sent some to my LFS to test and they had the same numbers as I did. I use Elos test kits and they use Hanna meters and salifert. It is still a mystery to me as to what happened. Good luck man. I am going to follow along and see what responses people give, other than Alk,PH swings. Which it seems that NEITHER of had.

I'm with you...I'm curious to see what theories people may have other than Alk/pH. We already know that these two factors have a lot to do with the chemistry of the tank and health of the corals. Even more importantly drastic changes in these..

the number one killer of all coral that noone has mentioned is temp.....being that it has been getting cooler in the evenings has your temp had a swing that could have caused this? do you have any electricity leaking into your water column....could also be bugs...i have seen tanks with aefw cause entire colonies to rtn overnight......

My temp does not swing more than .1-.2 degrees. I'm hooked into a ReefKeeper and have an alarm set for any changes more than .5 I've woken up several times in the middle of the night and my temp is constant at 79. Also, you mentioned pests. The pest would have to be something other than monti nudis and AEFW. The first coral to go was a seriatopora - AEFW don't like those. The 2nd coral was an encrusting monti...AEFW don't like those either

what is your dkh just out of curiosity and how are you checking it?

dKh is 7.7 with Salifert and 7.8 with Elos. It has been at the same level for almost a year.

I'm curious to see ideas/theories OTHER than dKh or pH or common pests such as AEFW.

 

[islander84]

i have seen some sort of pest demolish the whole underside of a birdsnest colony in no time....along with encrusting montis(5 to 6 inch colonies) and it starts off with just a few eaten spots and then poof rtned....also other various acros but not all only a select few...ora teal stag few small eaten spots then poof rtn....wild tricolor...carls candlelight....purple haze monti, sunset monti, setosa, purple cap.......but havent touched red planet, pink lemonade,blue voodoo and a few others....?

Did you notice any signs of missing flesh or anything prior to this?

 

[Joe Knows Reefs]

There were no signs of poor health whatsoever. Actually, I would have said that the birdsnest was the healthiest. It came as a small frag a year and a half ago and grew into a large colony.

Sent from my PC36100 using Tapatalk

 

[bella127]

I read about a study that was linking VSV dosing and RTN . It was an interesting read I'll try and find the article .

 

[Joe Knows Reefs]

I read about a study that was linking VSV dosing and RTN . It was an interesting read I'll try and find the article .

Yes please

Sent from my PC36100 using Tapatalk

 

[EW_Fish]

I'm having the same problem. Have you found anything out or is it still doing it?

 

[jcdeng]

did you put new corals into tank recently? they could very well have brought in a bacteria strain that is new to your tank. And some can fight it off and others just dies from the infection. I am only spectculating cuz the RTN seem to move from 1 onto the other. Water parameter issues would affect your corals (the ones that died at least) at the same time if its that bad.

 

[svt stang]

This is something I have also struggled with over the years from all the reading have done it all points to bacteria and once a coral starts to go it can infect or harm a bunch more. any swings in elements temp all can make it happen. one thing I have been doing in my sps tanks is keeping indicator corals one frog spawn, and one yellow tort if the frogspawn starts not looking good or closing something in the water colume is not right, if the yellow tort fades or closes up it again leads to water quality.

 

[EW_Fish]

All other corals look fine. one of my favias lost some skin but thats about it? How can you treat the bacteria?

 

[reef80]

I sincerely do hope that more research and findings are in this area. I can have a mini colony broken into two frags...All in crust and then...boom one of them decides to AWOL and dies. I wish there were better explanations...but most you are definitely onto something. I've seen so annoyed. I'll have acros encrusted for 1-3 months and then next day...either stn or rtn. I've determine all of the possibility. ..like bugs swings and so on and on and can't figure it out. Sometimes gluing the base help....just my venting...sorry.

 

[EW_Fish]

I sincerely do hope that more research and findings are in this area. I can have a mini colony broken into two frags...All in crust and then...boom one of them decides to AWOL and dies. I wish there were better explanations...but most you are definitely onto something. I've seen so annoyed. I'll have acros encrusted for 1-3 months and then next day...either stn or rtn. I've determine all of the possibility. ..like bugs swings and so on and on and can't figure it out. Sometimes gluing the base help....just my venting...sorry.

Yeah, I keep getting people telling me its swings or bugs when I know its not. I think mine is related to stray voltage but not 100%. I'm in the works of getting new equipment.

 

[Pete polyp]

I nuked over a dozen acro last year by overuse of aluminum oxide phosphate removing media.