What the heck happened here?!


New member

I woke up this morning to find my setosa frag like this. It was perfectly fine just 6 hours ago. I've had this piece since RAP, so what is that, about a month?

I did have my peppermints spawn last night, and I took my skimmer off for the night, so that maybe my fish can have a nice breakfast when they wake up. I don't get how that can affect this though. Did the larvae die off already and cause a spike?

What the heck?


New member
Those are cloves, and the setosa has always been in that exact spot for the past month. It has been growing very fast actually in that spot, almost as fast as my orange cap. So I'm going to say those cloves aren't a problem.

Edit: I just put my skimmer back online, and it seems to be cooking up something nasty.
Could die-off do this to my setosa? The odd thing is, none of my other pieces are affected.


New member
How are your other sps doing? Such fast necrosis appears if there are issues with alkalinity.

Regardless, I would move it from the current location, that mushroom will be problematic when it grows out, it will kill the tissue of your setosa in seconds.

It is hard to say if the cloves were a problem. I have had soft corals near stonies just fine, then one day they decide to attack each other.


New member
Like I said, the other sps are looking fine. Would it be better to pull the setosa out, so that it doesn't trigger a tank-wide RTN response? Or should I just move it away from the softies?

Edit: I just tested my alkalinity right now, same as always. 11 dKH.


New member
Can RTN trigger a tank wide response? I lost SPS before to RTN, one after the other. Maybe I should have just removed the sick coral.


New member
That does look like melting, not predation. Could be chemical warfare or a water chemistry problem. I'd do a quick ammonia and nitrite test if you have it, along with verifying alk, ca and mg just to be sure.

Thing about RTN like that, the corals can look fine for a long time then just blow up. Monti's are a bit rarer in doing that though.

I've never seen a monti blow up like that before though...


New member
I don't know what's going on, but my tank's been on a steady decline after.

During my long Thanksgiving weekend off (no dosing for a week), my alk dropped to 8 dKH. Stuff were slowly RTN and even when I got back and got my parameters under control and new carbon switched out, things kept RTNing. :(

Salinity 1.025
Calcium 420
Alkalinity 10 dKH

Lost a pearlberry, grape nasuta, a turaki, a pink formosa/stag, and a tenuis so far. Fingers crossing that the rest stay ok.
Unrelated? My peppermints spawned right before this mass RTN again. -_- I'm starting to think my peppermints spawning is a sign of something bad.

Any advice on what else I can do to help stop RTN?


New member
I highly doubt its the mushroom... Look at where the bleached part is.. Its facing the cloves. If it where the mushroom, it would have stung where the mushroom is(if that makes any sense). And also, (s)he said that its been in the same spot for months without ill effects...

You may want to test your ammonia and nitrate. It could also have been a build up of DOM's since your skimmer was off and it seemed like there was quite alot for your skimmer to skim.

If i where you right now, i would cut away the parts that look dead and leave what still has color. Throw away any dead corals in the tank and perhaps do a water change?


Certified Stick Killer
Mew, I had a similar issue a few months ago (you can check my thread). From what you’ve said it sounds like a water / parameter issue to me and I think that it is unlikely due to a spawning (spawning is usually a good sign). What turned the corner (knock on wood) for me was 6 straight weeks of large water changes in an attempt to flush out whatever contaminant was in the display. I would also check your sump for something that fell in and your equipment for any sign of corrosion. Good luck.


New member
Oh I guess a rather important piece of info I should mention is that this is a 10 gallon tank, and I do weekly 20% water change.

Alright, I'll try a series of water changes and see if it helps some. Thanks for the suggestions!
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Premium Member
Move the Mushroom PRONTO!

Thats what I was going to say. The mushroom could easily have done that. It didn't even have to be a sting exactly. It could just be stressing it enough to STN. My bet is on the shroom. Or some type of parasite.