Rtn/stn

[iap]

Hi. Does anyone have any photos of rtn/stn? I ran a search but didn't come across very many. The reason I ask is because I woke up this morning to discover 3 of my corals with what looks like rtn/stn I believe. My question tho is I caught a crab not to long ago hanging out on one of my millis and it was going to town on it and where he had eaten it looked like what I think rtn/stn would look like. Can those two thing look similar in nature?

I fed my corals some oyesterfeast last night, turned off some of my powerheads and seen the oysterfeast hanging pretty thick on some of the corlas, the ones in question, and fell asleep on the couch without turning the powerheada I had turned off back on. Well I know that I have 2 more dang crabs in my tank that I have seen and need to catch. Is it possible that the crabs came out and ate the oysterfeast off the corals and then began to eat on the corals? The rtn/stn isn't at the base or the tips, it's in the middle of the corals like last time where I caught the other crab in my milli. Does rtn/stn always start at the base or the tips, can it just start anywhere on the corals?

I went ahead and cut some frags off the corals just incase I do lose them. Sorry for my rambling it's just that the tank was going so well so far and I'm hoping that it's just the crab that did this and not something else.

Ca - 460
alk - 10.9dkh
mg - 1390
sg - 1.026

 

[Atomikk]

Look at this, which I wrote.

http://blog.fragd.it/2009/11/10/stn-and-the-real-issues-part-1/
http://blog.fragd.it/2009/11/12/stn-and-the-real-issues-part-2/
http://blog.fragd.it/2009/11/13/stn-and-the-real-issues-part-3/

There are numerous things that can contribute to STN, so read through them and come back to discuss.

 

[iap]

Ok good read. My temp doesn't really swing, 79 - 81. I have an ato so my sg is stable. I was/am testing for alk quite frequently because this is a young system and I'm trying to figure out what I need to dose or if I do.

Recently I've added some pickling lime to my water storage for ato. I need to test daily now to see what this does to my sytem.

I also recently added a phosban reactor. I had my water tested from a local reefer with a Hanna meter and it was 0.15. I had the phosban reactor running for a week or two and only put in a half a cup of rowaphos for my 110g setup. Well obviously it wasn't enough so my buddy that tested the water suggested I add more rowa to the reactor. So I now have 1 1/2 to 2 cups in there. So stripping phosphates to quick could cause it but I'm not even sure that they have because I only have the API phosphate test and I can't read those colors to save my life. Before when I tested with it I thought it was at 0 but the Hanna told otherwise.

 

[Atomikk]

Yes, that could be it. Corals need phosphorus to live (in small amounts). Take it offline, and feed heavily for about 3 - 4 days. Skim well while doing this.

 

[iap]

I tested with the API and had my wife look at the color chart and it's in between 0 and 0.25. So my system isn't stripped of phosphates I don't think. And I doubt not even a full day of the phosban reactor it would get rid of all the phosphates that quick.


So could it be conceivable that it's not rtn/stn and it really was the crabs going after the oyster feast covered on the corals that caused the small amount of damage. The damage is only done to 3 frags out of about 30 and those pieces that had oyster feast on them are on the rocks that crabs hide out on.

I really hope this is what it is and like I said the only reason I think so is because it looks like the damage on my rose milli that I know was caused by a crab that I let hang out on the milli because i watched it for a while. I did so because the lfs sold it to me as an acro crab on the frag. Turns out it wasn't an acro crab after all and he was in there picking and eating at the frag.

Anyone else experience this or what? Nobody has had a crab do damage to corals?

 

[Bugzme]

So if you have STN what do you do with the coral? frag the bad spots off of it? Will it live if it is fragged or is the stn in the whole coral?

 

[Atomikk]

With STN, its best not to touch any parts of the coral. Let it heal itself. Fix the parameters (or do water changes) and see if it rebounds. But if the necrosis is quick, then yes I would act fast. You would cut the parts that are healthy, approximately 1" above the dead parts.

 

[iap]

What is the timeframe for stn? Days, weeks, months?
And how bout rtn? Hours, days?

 

[Haksar]

What if the coral has STN and now brown algae is growing it,will you still frag it.
I have had cases where corals have returned back to life even after browning up.

 

[Atomikk]

What if the coral has STN and now brown algae is growing it,will you still frag it.
I have had cases where corals have returned back to life even after browning up.

I would cut the dead parts off, as you don't really need them, and could stimulate axial corallite growth.

 

[Atomikk]

What is the timeframe for stn? Days, weeks, months?
And how bout rtn? Hours, days?

It all depends on the type (if you can call it that). It could take days or months.

 

[tate1]

I have had an entire large colony RTN in 3 days. When I tried to cut off what was still good (and cut it at least an inch above the dying tissue) it excellerated the RTN on those frags alone. It actually hapened on 2 colonies. I've never had that happen before. Prior to those 2 colonies, I almost always saved part of the colony from completely dying.

 

[Haksar]

I would cut the dead parts off, as you don't really need them, and could stimulate axial corallite growth.

Thanks Atomikk..

 

[Atomikk]

Anytime. If you have more questions, ask away.

 

[ingtar_shinowa]

if they are stn'ing, meaning there is still tissue today, let them heal. My hydnophora colony i thought was a gonner, but now its healthy and growing back over the exposed skelly, im pumped becuse it was my fiancees favorite, though now its the setosa frags lol