Spontaneous RTN?

[scolley]

Do acro's RTN without an evident trigger event?

I've got small acro frag (maybe 1.5" high) that's been in my tank a few months. It had a tough time in shipping due to weather delays, and after about 2 weeks in low light to recover, I moved it to what I thought would be a good position. The bottom third had STN'ed, but it seemed to be hanging in, even slowly coloring up, though the bottom third remained white.

Bottom line, it's been stable for a couple of months as I observed slow - very slow - improvement. But today it's a white chunk of rock. Yesterday it looked fine (all things considered). So this happened fast.

All my other SPS look ok. No other coral changes. And no trigger events I can point to... stable temp, stable ALK, Ca, Mg. No light or flow changes. I DID upgrade my skimmer last week. But if anything, corals look better for it.

Is this normal? An acro just spontaneously RTN'ing like that? While other acros and other SPS in the tank remain stable?

Thanks.

 

[daveonbass]

Yup that same thing just happened to me. I had a strawberry shortcake yesterday...today its bleached and gone.

 

[franklypre]

Some stuff makes it and some does not, is there a cause for it "yes". However it happens to everyone.

 

[scolley]

Yup that same thing just happened to me. I had a strawberry shortcake yesterday...today its bleached and gone.

Wow. Mine WAS a Strawberry Shortcake. Or at least the vendor said it was... Hard to tell from the look if it.

Oh... I'm not saying there was no cause. EVERY event has a cause. My point is that I cannot find an APARENT cause, and no other corals appear to be bothered.

 

[TucanSam007]

Yeah it's just one of those things that just happens unfortunately . For some reason I have a aussie Highlighter acro that has stn super slowly. Everything else just looks great. I stopped beating myself up over it and won't be too upset if it ends up dying overnight one of these days.

 

[ek9vboi]

Same here... my pearl berry went quick. I'm not sure what to make of it, looks like there is some tissue left on the frag but only where the polyps would come out. It's still in the tank for now.

 

[scolley]

Its just wacky.

I'm relatively new to acros, so I'm learning. But seeing something go down fast with no discernable trigger event was a surprise.

I suppose its less suspect when you consider that it was a recovering coral in the first place. Maybe if its not doing well in the first place, this genus - which I'd normally fragile anyway - becomes super sensitive to tiny changes in conditions that do not cause a hiccup in healthy corals.

I don't know certainly... Just speculation.

 

[29reef]

It's happened to me more times than I'd like to remember over the years. Some frags make it, others just give up one night. Sometimes it's easy to tell why, others just leave you feeling like a failure

It's mostly the wild corals that do it, they just aren't used to aquarium conditions like other tank grown corals.

 

[scolley]

This was a Dr Mac frag. Looked like crap from day one - again due to shipping. I tried to get them to replace it and was told "browning in shipping happens." That's my last order there...

Anyway, it was not remotely encrusted to its plug. Just a glued on frag. So it very well cold have been wild. If it were aquacultured, I'd have expected a little encrusting.

 

[scolley]

The plot thickens...

Under nothing but royal blue LEDs tonight I could see that the underside of the frag is not entirely dead. The bottom quarter, hidden from light above, still has tissue on it!

Previously this had looked dead to me... its tissue was so light as to look white. But now with truely white bone above it, it's clear that it's still tissue covered.

So that drives light up to the top of the possible offenders. Yet nothing has changed in my lighting. But there is no denying that it's the coral directly exposed to light that RTN'ed.

Hmmm...

 

[scolley]

The ONLY thing I can think of I didn't mention, only because it was not unusual... I do it 2-3 times a week. I dosed a small amount of KZ Pohl's Coral Snow - 1/2 of the minimum recommended daily dose. 1/8 of the max daily dose. So not much.

Anyway, it temporarily clouds the water, but when it clears its crystal clear. That said, my water is always very clear.

The instructions say, "...be aware that the clear water in combination with intense lighting can initially burn your corals. We recommend otherwise your lights for about a week if that occurs."

I'd like to think that was not the problem. I do it often, and everything else is fine. But its all I can think of that has anything to do with light.