Early intervention? Rtn/stn

[Reef Frog]

I have been adding some SPS to a 3 year old LPS dominant tank over the last few momths. 2 Acros 2 Stylos 1 Setosa & 1 Monti Cap all doing well & growing under T5 in a very healthy & stable 65g. I have added a small colony of "Tabling Acro" and have spotted a streak & patch of white exposed skeleton. Oh no RTN!

I've searched this forum & others and found several threads on the topic but the info is somewhat fragmented. Hopefully this thread can help consolidate what is known about this condition.

"¢Is there agreement on the cause? Theories on the cause?
"¢Bacterial or animal parasites a factor?
"¢Is non ideal placement a cause, i.e. flow & light issues?
"¢I've heard ALK levels or swings blamed. True? My ALK is steady @ 8.0 dKH +/- 0.4 dKH Ca 410. Mg was @ 1200ppm & got it to 1400ppm dosing 20ppm per day & have stopped.
"¢Is it advisable to frag the coral? Or just clip off affected areas?
"¢Does it ever stop on its own?
"¢Any other cures or treatments to stop its progression?
"¢So what do you do if/when you see signs of RTN/STN in your tank?
"¢Is it most common in newly introduced SPS or does it frequently pop up in long term established colonies?
"¢Do you know of top notch threads or articles on the topic?
"¢Any tips for future additions?
"¢Can it spread in the tank? Should I get it out ASAP?
"¢What can I do if anything?
"¢Can anyone share tales of success or failure?

It would be great if someone could take a stab at any of the questions above.

Here are the details of my RTN case:

"¢Added it within the last week or so. No acclimation issues observed.
"¢RTN area seen 1 day ago. Looks like a small expansion occurred in 24 hrs.
"¢Quick acclimation by incremental 10% water exchanges done in 25 minutes. LFS salinity 1.024 my tank 1.026. Temps stable in 15 min car ride & I kept temps stable within 3F at all times. Did a 5 minute dip in Revive & then Seachem Iodide dip which claims to be gentle. Brushed base w soft toothbrush & drizzled a few drops of 3% peroxide on ceramic frag disk to hopefully eliminate any eggs. No peroxide touched any live tissue. Then into the tank. No stress observed, no color change, I think I see feeder polyps poking out n
"¢A recent arrival at LFS with no damage or issues under T5
"¢98% of tissue unchanged now with good color but I think it's spreading. Have a streak on an outer branch & a patch under that near the base.
"¢Placed on a flat rock 12" under T5 that are 4"' above water surface. Flow was only moderate as acans & trumpets can thrive there. Moved it to a more direct flow with just a small decrease in light by itself on an intank frag rack. Good skimming & use a filter pad on rotation.
"¢in a clean but fed tank running GFO for a few years & no GAC at this time. Small fish load, no stingers present, no softies except for a few zoas. PO4 .04 ppm & no algae issues, no nipping fish. Nutrient levels are SPS quality but not too low as LPS look great & are puffy & extend feeders.

So there is all the info &'am hoping for some enlightenment! Are the odds such that in destined to lose this small colony or is there hole. Anything I can do? I'm willing to experiment if needed. Thanks for reading & any comments or advice you can add.

 

[Reef Frog]

Here is an image that I referred to as a streak. It's slightly left of center with some zoas in the background.

https://www.dropbox.com/s/3q59dplfx28n8pi/Photo Dec 16, 8 46 21 PM.jpg

 

[ampemployee1]

I would consider clipping that branch off before it progresses to the rest of the frag.

 

[Reef Frog]

I would consider clipping that branch off before it progresses to the rest of the frag.

I am thinking that is the only thing to do. I've included a pic link to the bare patch by the base. Looks the same as it did 24 hrs ago but am thinking it should go. This means essentially cutting it in half. I think I'll get rid of the plug base too.

Clear Photo:

https://www.dropbox.com/s/5g0k4gl5nv5kh3b/Photo%20Dec%2017%2C%207%2006%2051%20PM.jpg


Never cut an SPS before & the branching is very dense. Hope I don't mangle it as my tools aren't ideal but should work. Do you think it's safe or wise to keep the RTN half in the tank to observe it? I have no idea if this ailment is contagious. Anybody?

I'd be willing to experiment on the ailing piece. Any idea? Maybe treat the spots with a antibacterial? Any ideas to increase the chances with the unaffected part? Thanks.

I suppose dipping at this point on the healthy half will do nothing useful.

 

[tdb320reef]

What is your N03?

 

[tektite]

The tissue recession has started at the base as well. What flow is it in? What's your daily temperature swing?

 

[brad_G]

+1 on the base rtn. You can use super glue to stop rtn. That or fragging a healthy piece is about your only options at this point.

 

[Reef Frog]

I didn't test NO3 today but it is usually not detectable as I have just a few small fish. But I will check it and post. I am confident it won't be detectable. Is there high NO3 & RTN relationship. PO4 at .04, GFO & very little algae.

My temp is pretty stable. 78F set point. Min/max swing is 77F & 80F.

It was in medium flow with nothing close by to block it. I have 2-3 month old acros and long term LPS like acans & trumpets in the same flow rate with good results. But I did suspect flow might be too low and moved it into direct strong flow but not crazy high flow. Is there a relationship between RTN & flow?

Thanks for the responses so far.

 

[tektite]

FYI some acros respond poorly to iodine based dips, might be part of the issue.

 

[Reef Frog]

FYI some acros respond poorly to iodine based dips, might be part of the issue.

Ah ha. I did this to label instructions. Never heard that despite all my reading. The iodide dip was done maybe 5-6 days ago, wondering if that interval before symptoms is typical.

 

[Reef Frog]

+1 on the base rtn. You can use super glue to stop rtn. That or fragging a healthy piece is about your only options at this point.

I have heard this suggested in the past for some kind of coral malady. Can't remember the details. Sounds reasonable. I just may do this as an experiment on the affected half.

 

[Reef Frog]

For those who have experienced RTN or STN:

Can you remember how long it took from coral introduction into your tank and the first symptoms? Did you frag? Any part of the coral recover permanently?

So far no one has mentioned lighting or animal or bacterial parasites.

I am getting ready to cut & deciding if I should cut away the stalk & cover the patch with super glue, or just cut off the entire half with both infected areas.

Then I need to decide if I should keep the infected part in the display tank. I'd like to see if covering the affected areas with crazy glue works but don't have a suitable isolation tank ready.

 

[UTCReefer]

Ive experienced it from time to time. The best thing to do is make several frags of the coral as far away from the affected area as possible. If you are lucky a few of them will survive.

I would also check your SG, and then calibrate your refractometer and check it again. One of the things that prolonged high SG caused in my tank was RTN or STN.

 

[Reef Frog]

Ive experienced it from time to time. The best thing to do is make several frags of the coral as far away from the affected area as possible. If you are lucky a few of them will survive.

I would also check your SG, and then calibrate your refractometer and check it again. One of the things that prolonged high SG caused in my tank was RTN or STN.

I calibrate with RO water for 1.026 salinity at a room temperature of 72F to 73F. I'm going to buy 1.026 testing solution tomorrow and check and will report back. This makes sense. I'm getting the idea this may be one of those things that has multiple causes.maybe I should drop back the salinity .001 as good measure but not sure on that.

When you say you get it from time to time, are you talking about established colonies or new(er) additions? Thanks.

 

[tdb320reef]

I didn't test NO3 today but it is usually not detectable as I have just a few small fish. But I will check it and post. I am confident it won't be detectable. Is there high NO3 & RTN relationship. PO4 at .04, GFO & very little algae.

My temp is pretty stable. 78F set point. Min/max swing is 77F & 80F.

It was in medium flow with nothing close by to block it. I have 2-3 month old acros and long term LPS like acans & trumpets in the same flow rate with good results. But I did suspect flow might be too low and moved it into direct strong flow but not crazy high flow. Is there a relationship between RTN & flow?

Thanks for the responses so far.

No but in my case it was 0 or too low N03. It follows the same pattern GFO, GAC rox .08, 0 nitrates and STN/RTN. It always seemed that the part of the coral shielded form light such as the base would STN. Id start to ramp up on my Mysis and Oysterfeast feeding and it would stop. My guess is that these areas utilize water nutrients(yellow phenol and nitrogen) to survive.

 

[Reef Frog]

Ah ha again. This is what I am having. This rings true. Indeed the "patch" was at the base shielded from light. The branch wasn't shaded but was at the margins of the T5 light spread.

I am going to check NO3 & see if I can't boost a reading of about 5ppm if needed. Considering maybe turning off the skimmer and feeding some more. Got to make sure I don't over do things and mAke the cure worse than the disease!

 

[Reef Frog]

Well I tested and my nitrates are undetectable & confirmed low PO4 on a Hanna meter. My ALK does flirt with a 9 dKH reading. So I am beginning to conclude that the low nutrients with the higher than NSW ALK levels may indeed be the driving factor in my RTN, based on this thread and others I have been reading.

It's funny as 2 or 3 years ago I never imagined I could ever strip nutrients down so far or that it would be a problem. So after trying to deal with my immediate issue, I'm thinking towards the future so I can avoid this problem with SPS.

My fish & corals really don't need more food. I have room for more fish so that's a possibility. I'm also considering skimming less and possibly putting my GFO reactor on a timer for a 4 to 6 hour period of OFF TIME distributed evenly throughout 24 hours. But I am nervous about monkeying around with such an otherwise successful thriving system - I don't want to get on a nutrient see-saw after beating back algae for an extended period.

I saw some posts suggesting dosing amino acids and such. I have always kind of put this into the snake oil category or at least the "not of much use" category. But it is an organic compound after all and i am thinking its worth a try, it couldn't hurt and I can abandon the effort easily enough if it starts to cause an algae bloom. Any opinions on using amino acid or other similar products? Or any success or non-success stories?

But in any event I'm thinking upping the nutrients (but what is an ideal NO3 level?) and cranking back my ALK doser just a little bit, slowly. Good plan? Thanks.

 

[Reef Frog]

I didn't frag my victim yesterday but will be doing so today. I've decided to make several frags and test them in more & different areas of light, flow etc. maybe I can increase my odds that at least one frag will come through. Unfortunately another ORA acro is showing early symptoms of RTN so he goes under the knife as well. Oh boy.

I will also hopefully be able to get salinity testing solution locally today to see if I truly have a hyper salinity condition.

It sounds entirely plausible that a 3 part cause - low nutrients, high ALK & salinity all combine to create this problem. Kind of like gardening with finicky plants...Plant A can handle some drought just fine. Put it in poor soil and it might just hang on but doesn't thrive. Change one more factor like too much or too little sunlight and its a gonner.

Has anyone out there ever had an RTN case stop in its tracks leaving part of the coral alive? Can tissue ever recolonize bare skeleton? Thanks again for the thought provoking ideas.

 

[tektite]

Could be something like a vibrio infection too. Was the other coral fine until the addition of this one?

I know its nitpicking, but you have STN, not RTN RTN cat kill the coral in a matter of hours, STN is more days-months time range


In answer to some of your questions:

Is there agreement on the cause? Theories on the cause?
50 million causes. Flow, light, temp, alk, cal, pests, diseases, predation, allelopathy...

Bacterial or animal parasites a factor?
Can be. Pests like AEFW and vibrio infections (contagious)

Is non ideal placement a cause, i.e. flow & light issues? Is there a relationship between RTN & flow?
Can be. Though too high or low of light tend to cause bleaching/browning before recession begins. Too high of flow can blow the tissue off the coral, too low can cause recession.

I've heard ALK levels or swings blamed. True?
Stability is the key to SPS. Alk swings can definitely contribute. The more stable you keep your salinity, alk, cal, and temp, the better for the SPS

Is it advisable to frag the coral? Or just clip off affected areas?
Clip off affected areas if possible (like recession on tips), frag coral if recession is more widespread or more prevalent around the base.

Does it ever stop on its own?
Sometimes, if the cause is environmental and not pest/disease related. The majority of the time, no.

Any other cures or treatments to stop its progression?
Fragging, some dips.

So what do you do if/when you see signs of RTN/STN in your tank?
Check parameters first, make sure everything's stable especially alk and cal levels. It is especially concerning if the coral has been in the tank for awhile, a new coral not so much. You may have no idea what conditions the coral has been in (if from a LFS) that may have stressed it too much.

Is it most common in newly introduced SPS or does it frequently pop up in long term established colonies?
Varies, can happen in both situations.

Any tips for future additions?
Be careful with dips (some kinds of acros respond very poorly to iodine based dips), quarantine before adding to the DT.

Can it spread in the tank? Should I get it out ASAP?
If pest/disease related, yes it can spread. If environmental, not unless those same environmental conditions hurt the current SPS. Could be it was too stressed before your purchase.

Can you remember how long it took from coral introduction into your tank and the first symptoms? Did you frag? Any part of the coral recover permanently?
Varies too much to have a useful answer as far as time. Fragging definitely helps, if there is polyps/flesh left there is potential to recover after the cause has been eliminated. If the flesh is gone, no.

I am getting ready to cut & deciding if I should cut away the stalk & cover the patch with super glue, or just cut off the entire half with both infected areas.
If there's a good portion of the coral with no recession yet, frag that off and make it its own colony.

Then I need to decide if I should keep the infected part in the display tank.
If you think its environmental, keep. If pest/disease, throw.

Has anyone out there ever had an RTN case stop in its tracks leaving part of the coral alive? Can tissue ever recolonize bare skeleton?
I've had some STN stop when the cause was environmental and I fixed the problem. For regrowth, if the tips are gone, cut them off. Parts of branches or base, may or may not grow back over. The coral usually responds best to having dead areas cut off vs. trying to have it regrow over those sections.

 

[Outdrsyguy1]

I had a similar problem from an alk swing. Wasnt paying attention and had too many frags in a qt with no dosing and over a couple weeks alk went from 7.8 down to 6. stn started and kept going for a week or so even after I got things back up to 7.7+. shaded areas always experience 99% of the stn.

i've had coral grow back over the dead part but most sucess when there was little to no algae growing on the coral, once the hair algae starts you might as well cut it off, very little success beating back the algae.

You aren't dosing stuff into the tank near there by chance? I had some stn/rtn from dosing near the corals (~6+ inches away, no sump...)