Is STN a disease in your water?

[TwentyfiveCents]

I get the treatment and causes of stn/rtn, if it is bacteria causing your stn/rtn than wouldnt a UV filter hooked up to the system return help prevent the issue?

 

[Fishfinder]

Anyone ever done iodine dip for STN?

 

[Hans-Werner]

I am quite sure that STN is not a bacterial disease but an imbalance of deficiency. It is quite typical that it occurs when phosphate concentration is sinking rapidly. Not rising phosphate concentrations are damaging corals but rapidly sinking phosphate concentrations. You can easily tell it when you get corals from a high phosphate system (with coral rubble reactor or phosphate dosing) and put it into a low phosphate system. Corals stop growing and get STN from the base. High alkalinity enhances or causes STN when phosphate concentrations are low.

 

[HB AL]

Anyone ever done iodine dip for STN?

Yes and it has been successful in alot of cases but not all. I use the brightwell aquatics coral dip. I figure it cant hurt if stn starts to affect a piece of coral.

 

[BantyRooster97]

My STN came on strong (several frags & colonies) when I removed the rock that caused my phosphates to jump, however when the phosphates jumped I also lost 2 acros to RTN overnight and 3 of 4 montis that had been growing like weeds all greyed out (not sure if they are dead yet).

Also, I'm not dosing anything anymore. I had started to dose nitrates, but stopped when I started having problems. Only thing running is a CaRx.

 

[29bonsaireef]

IMO, and from my experiences I would say STN/RTN is caused from a bacterial infection. The corals health has to plummet first caused by unstable parameters or another cause other than the bacteria. Once weakened, the corals become susceptible to the bacteria, kind of like fish and ich.

 

[OriginalUserName]

Its a specific strain of the bacteria in the vibrio family. Ironically, this turns out to be the most prevalent bacteria family in the oceans and our aquariums. Im curious if its pheasable to completely remove this strain from a system when we have things going in all the time such as fish, corals, invertibrates, etc.

If it is that prevalent then it would come right back with new corals along with the nitrifying bacteria and everything else. I'm an SPS novice but it seems to be something that is benign until the coral is stressed. The relationship between bacteria and other living things is very complex. We have plenty of bacteria on our skin that could cause problem in an open wound, or gut bacteria that could cause problem if you ate it. STN/RTN must be caused by the coral losing some protective mechanism that allows this bacteria to grow out of control. (again, just an slightly educated guess)

 

[rosshamsandwich]

STN and RTN are two things that we still do not know much about in this hobby. STN/RTN is not a disease but a bacterial strain in our water and in the ocean, one of the most present bacteria in fact. When a factor occurs that stresses or weakens the coral(s) it gives the bacteria a window to jump in causing STN or RTN. Your best bet it to frag the corals but success has also been seen with temp and salinity changes. The bacteria does not like temps below 78 or salinity above 36. When kept under those two ranges many people have been able to recover large colonies.

thank you

 

[Graffiti Spot]

If anyone is having issues with stn or rtn, the best thing to do is to clip all affected areas on the corals and clip any new death as soon as you can. I also remembering reading about people having better luck fighting necrosis buy doing this and switching to kalk for all and calcium. Something about the ph boost and dosing saturated kalk helped in some cases. I had luck with it when I had issues once. I wish i could remember the article and reasoning behind the theory of it helping. But I think keeping ph above 8.3 or something like that was the main goal, and most had to use saturated kalk dosing to get their ph up for a good period of time.

 

[Graffiti Spot]

Also I like to use a couple drops of iodine in a container to soak the affected corals in after clipping. This really helps keep further infections from spreading.

 

[Graffiti Spot]

I am quite sure that STN is not a bacterial disease but an imbalance of deficiency. It is quite typical that it occurs when phosphate concentration is sinking rapidly. Not rising phosphate concentrations are damaging corals but rapidly sinking phosphate concentrations. You can easily tell it when you get corals from a high phosphate system (with coral rubble reactor or phosphate dosing) and put it into a low phosphate system. Corals stop growing and get STN from the base. High alkalinity enhances or causes STN when phosphate concentrations are low.

Really? I have never had issues with adding acros from high phosphate systems before. They actually have done pretty well and certainly didn't go idle or stn. Anyone else have the same issues as HW when buying frags from high phosphate systems?

 

[Flippers4pups]

Here's a good read on the subject I found some years ago:

http://www.artificialreefs.org/Corals/diseasesfiles/Common Identified Coral Diseases.htm

My experience with RTN/STN is that fragging the coral at the infection line/sight, removing the infected tissue out of the system. Try to keep the infected tissue from becoming loose and ending up in the water collum.
(Reports of infected corals infecting other healthy corals near by)

Dip the healthy frag in a iodine bath and then into a bath of bacterial meds. Rinse and back in the tank. This doesn't always work, because of the different strains of bacteria.

This video explains a little of that information about the bad and good bacteria that lives on each coral.


RTN/STN is triggered by environmental stressors: temp, water pramameter swings, toxins.....etc....
They weaken the corals immune system, from there it's strictly speculation, but in infected tissue, bad bacteria have been found. Its not clear if the bad bacteria ( vibrio strain in most cases) was to blame or something else and the bad bacteria was there to "clean up" the dieing tissue.

Coral disease research has found 1000's of different strains of bacteria (gram positive and gram negative) living on coral colonies. These strains differ from one part of a reef to another near by. It's almost impossible to isolate these strains, thus it's difficult to know exactly how to treat them.

Unfortunately there will never be a treatment or cure, most likely in the foreseeable future.


Hope this helps.

 

[The Opinionated Reefer]

I am quite sure that STN is not a bacterial disease but an imbalance of deficiency. It is quite typical that it occurs when phosphate concentration is sinking rapidly. Not rising phosphate concentrations are damaging corals but rapidly sinking phosphate concentrations. You can easily tell it when you get corals from a high phosphate system (with coral rubble reactor or phosphate dosing) and put it into a low phosphate system. Corals stop growing and get STN from the base. High alkalinity enhances or causes STN when phosphate concentrations are low.

Do the corals eventually get used to the low phosphate system and then start to grow if you can save them from stn?

Also at what point do high phosphates start to kill sps? My tank has been going downhill for a while and eventually, I got an icp, and turned out my phosphate has gone up to 0.6. I had been reading the tests wrong. The corals were all getting stn from the high phosphate.

 

[Ben Pedersen]

There are bacterial and non bacterial causes for both RTN and STN. For instance, one form of STN (white band disease) is bacterial and can be transmitted by hermit crabs. I also know that raising alk to quickly can cause similar symptoms. I am pretty sure that the recession caused by quickly rising alk is not bacterial. And there are several bacteria that can case STN.

Its complicated.

 

[Marc Pardon]

I am quite sure that STN is not a bacterial disease but an imbalance of deficiency. It is quite typical that it occurs when phosphate concentration is sinking rapidly. Not rising phosphate concentrations are damaging corals but rapidly sinking phosphate concentrations. You can easily tell it when you get corals from a high phosphate system (with coral rubble reactor or phosphate dosing) and put it into a low phosphate system. Corals stop growing and get STN from the base. High alkalinity enhances or causes STN when phosphate concentrations are low.

This is an old topic and your conclusion seems to be right but when we look at new investigation http://cris.leibniz-zmt.de/id/eprint/4590/1/Zhao 2021.pdf than is dosing nitrate a very bad idea?

 

[KK's Reef]

It's a disease caused by many potential factors. STN and RTN are usually caused by bacterial infection. RTN happens to everyone's tank. Healthy corals don't usually get them. Stressed ones are susceptible to bacterial infection. If your corals are still dying slowly you can dip them in antibiotics every day. Because you don't know what bacteria is/are causing the issue you can dip them in sea water mixed with a little bit of wide-range antibiotics like erythromycin and Furan-2. If you are carbon-dosing or dosing any amino acids, vodka, vinegar, etc that needs to stop too.

Curious about the point of stopping amino acid dosing. Does the aminos feed the bacteria?

 

[Hans-Werner]

Do the corals eventually get used to the low phosphate system and then start to grow if you can save them from stn?

Yes, but very slowly and I don't know how to improve adaptation. Once they are adapted they grow more slowly but normal. The key is to get new skeletal growth at all. Iodine may help, keeping the iodine concentration rather on the high side at 60 to 100 ppb but on the low side. But this is a bit speculative from my side, some observations but not well tested yet.

For the old part of the skeleton the prognosis is quite bad. I call it the "memory effect of the coral skeleton". Maybe it is the organic matrix, maybe it is the mineral structure of the old skeleton, but something seems to inhibit new growth on the old skeleton when phosphat concentrations drop. The best chance for new skeletal growth is on the growth tips and the growth zones. From there the corals may initiate new growth adapted to low phosphate concentrations.

This is an old topic and your conclusion seems to be right but when we look at new investigation http://cris.leibniz-zmt.de/id/eprint/4590/1/Zhao 2021.pdf than is dosing nitrate a very bad idea?

Yes, but in the oceans it is a much bigger problem. The problem in the oceans is that nitrate has two effects: 1) It supports algal growth which competes with coral growth for space and nutrients, especially phosphate and 2) it causes direct damage to the corals, especially when they are in short supply of ammonium and phosphate, which is caused by 1)!

In tanks in the best case it works as an oxidant like hydrogen peroxide killing cyanobacteria. In many tanks it is just chasing numbers without any effect. The nutrient load in the water is high and, if at all, coral growth is limited and reduced by trace elements. No macro nutrients limiting coral growth, corals hardly make use of nitrate as a nutrient. No nitrate effects to the corals.

Does the aminos feed the bacteria?

Yes, for sure! The bad thing is that amino acids also feed opportunistic bacteria, rotting bacteria, which may attack also living tissue when they get abundant. So rather be careful with amino acids.

 

[The Opinionated Reefer]

Yes, but very slowly and I don't know how to improve adaptation. Once they are adapted they grow more slowly but normal. The key is to get new skeletal growth at all. Iodine may help, keeping the iodine concentration rather on the high side at 60 to 100 ppb but on the low side. But this is a bit speculative from my side, some observations but not well tested yet.

For the old part of the skeleton the prognosis is quite bad. I call it the "memory effect of the coral skeleton". Maybe it is the organic matrix, maybe it is the mineral structure of the old skeleton, but something seems to inhibit new growth on the old skeleton when phosphat concentrations drop. The best chance for new skeletal growth is on the growth tips and the growth zones. From there the corals may initiate new growth adapted to low phosphate concentrations.

Yes, but in the oceans it is a much bigger problem. The problem in the oceans is that nitrate has two effects: 1) It supports algal growth which competes with coral growth for space and nutrients, especially phosphate and 2) it causes direct damage to the corals, especially when they are in short supply of ammonium and phosphate, which is caused by 1)!

In tanks in the best case it works as an oxidant like hydrogen peroxide killing cyanobacteria. In many tanks it is just chasing numbers without any effect. The nutrient load in the water is high and, if at all, coral growth is limited and reduced by trace elements. No macro nutrients limiting coral growth, corals hardly make use of nitrate as a nutrient. No nitrate effects to the corals.

Yes, for sure! The bad thing is that amino acids also feed opportunistic bacteria, rotting bacteria, which may attack also living tissue when they get abundant. So rather be careful with amino acids.

At what point do phosphates start to kill SPS?

I have two tanks, in one the phosphate got to 0.6 and a lot of my sps started to get STN from the core or base and die. I am trying to reduce the phosphate but in order to save some I fragged the acros and moved them to the second tank which has low phosphate and I have noticed STN from the base just as you described. So they seem to be dying in either tank.

 

[Hans-Werner]

At what point do phosphates start to kill SPS?

I have two tanks, in one the phosphate got to 0.6 and a lot of my sps started to get STN from the core or base and die.

I am not sure whether 0.6 ppm of phosphate was really the cause. I have 0.3 ppm in one system without any problems and my colleague had 1 or 1.5 ppm phosphate in a nano, largely without major problems.

The problems after moving the corals to a tank with low phosphate is what I would have expected.

Iodine and its ratio to phosphate maybe could be a factor. If iodine is low, increasing the iodine concentrations to normal (60 ppb) to slightly high levels may help.

 

[The Opinionated Reefer]

I am not sure whether 0.6 ppm of phosphate was really the cause. I have 0.3 ppm in one system without any problems and my colleague had 1 or 1.5 ppm phosphate in a nano, largely without major problems.

The problems after moving the corals to a tank with low phosphate is what I would have expected.

Iodine and its ratio to phosphate maybe could be a factor. If iodine is low, increasing the iodine concentrations to normal (60 ppb) to slightly high levels may help.

It may have been above 0.6 that is just the reading i got at one point. But I have AEFW also in the tank and what was happening was they would cause damage and the high phosphate would cause the acro's to get algae growing on the damaged parts of the coral. Some kind of infection would then set in and start to stn. It was only Acropora that were dying due to the super high phosphate levels, other sps were perfectly fine. Not all acro's only some.

But what you say ties up with my experiences so far. The tank was doing really well for a while and I managed to grow out massive Acropora colonies from frags. During that time my nitrates were virtually undetectable on hobby grade kits and my phosphate sat around 0.1 to 0.16. Everything grew well and looked great at those levels. Low Iodine has always been a problem in my tanks though. I am trying to reduce the phosphate down from 0.6 to around 0.12 will that likely cause more stn? And i have started dosing small amounts of phosphate in the other tank. The problem with having such high phosphate was that aby frag wrack or pump would get covered in algae in no time and that would kill frags etc.