RTN vs STN?

helitaiwan963

New member
Hey guys,

Can anyone explain to me what RTN and STN stands for and means? I've been reading about causes of SPS death and these come up but no one explains what they are... I'm new to SPS and Added a few SPS frags over thanksgiving break.

I'm back home and My digitata frag and my little milli frag seem to both have grown a little bit... but with now they have some, what seem to be, dead or whitened out spots on the frags... I can't tell if it's RTN or STN...

Pics tomorrow when the lights come on.


-Eric
 
RTN = Rapid Tissue Necrosis

STN = Slow Tissue Necrosis

Not sure how to identify which is which, or even if what you are seeing is either.
 
One is rapid
The other is slow
:)
will keep spreading and kill entire coral most likely. Best to cut the healthy branch and save yourself a frag.
 
I'll take some pics to make sure tomorrow... The milli is a tiny frag already. I hope I can salvage a piece of the digi though.
 
Just be sure that it's loosing tissue and not just bleaching or browning. Sps will bleach on the undersides that aren't exposed to light. They will bleach and still have bleached polyps in chemical/ too high light situations. They will brown from shock and different chemical things in your water ( high phosphate for example). So really there are lots of different things that cause " white" spots. Make sure it's RTN before you frag the frags. If they are new frags it's most likely Tissue narcosis of some sort. Only thing you can do is frag off good parts and hope. If the white areas have polyps it's not RTN, so check your parameters and move it as low as you can in your tank (light shock can cause bleaching). Hope this is helpful!
Heidi
Woo sorry that was so long ;)
 
Most get stn due to bad params or maybe bacteria....if you have run, you'll know, it will kill a frag or colony in a matter of hours, there are some you tube time lapse videos if you search. Note, that stn typically starts from the base up, not the tips. If the tips are turning white, it's usually a sign of growth, not necrosis.
 
Hmm... That's good to hear it may not be rtn of stn. I'll have to take pics to see. I'm new to sps so I need some experienced eyes on this. These two are newer frags... But my other sps added at the sake time are doing great and getting drowth.
 
This is how RTN looks like,bare skeleton with no tissue left.This happened to me in less than 12 hrs. period.

IMG_6326.jpg
 
Holy cow mark... it made me sad to read that story myself. I can only imagine how it would feel walking home and seeing that...

But i did the best to get pics of the coral. I think mines slowly getting the way it is so it may be STN if anything... Pics uploading now.
 
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