Acro RTN...12 hrs from healthy to nothing!

[hometown9]

Any ideas how / why this happens? I lost 3x acros right next to each other, all within 12hrs! They had been thriving for 2+ years. Everything else seems ok (including other acros), and parameters all steady.

 

[AfaceInTheCrowd]

Where they touching?

 

[vetteguy53081]

Had to be an alk spike
Any recent changes ?
Water change
Dosing
Lighting?

 

[hometown9]

Yes but only in 1 small spot (left side of the bleached on). Is it possible for the entire colony to go nuclear and expel all zooxanthellae algae due to 1 area of touching?

 

[hometown9]

Had to be an alk spike
Any recent changes ?
Water change
Dosing
Lighting?

No changes and no alk spike that I could tell (consistently 10.5). No changes in dosing or lighting that I have been able to figure out.

 

[piranhaman00]

Did your nutrients bottom out? That alk is too high.

 

[vetteguy53081]

No changes and no alk spike that I could tell (consistently 10.5). No changes in dosing or lighting that I have been able to figure out.

Alk 8/9 recommended. A bit high and spikes will jump up and fall down quickly

 

[hometown9]

Did your nutrients bottom out? That alk is too high.

Been running that alk for 2+ years but will bring down slowly. And just those 3 pieces were destroyed...everything else (including 10+ other acros) are just fine.

 

[ScottB]

I hate it when that happens. But it does happen. Sometimes I just can't explain it. It is hard to determine causation so often because of the "delayed reaction" to a prior stress event.

Did the flesh come off or did it bleach/expel? Sometimes it is hard to tell.

Any chalise nearby? Any change in flow in the past few weeks?

Some will suggest that your ALK is high. Combined with high light (found at the top of the reef) and lower nutrient will cause a bailout. What are your nutrients like and how steady have they been?

 

[hometown9]

Given the other acros at the top are fine (see pic) I'm thinking it has less to do with nutrient swing, but like you said, who knows. I test daily (Alk, salinity, nitrate, phosphate, mg, calcium) and haven't noticed anything.

The flesh came off and that acro smell is now gone. Believe that will mean the piece is toast, which is unfortunate after growing it from a frag for at least 3 years. It's all encrusted on the rock so will just use a new frag attach point...or who knows maybe it'll come back.

 

[ca1ore]

Everyone will have their 'pet' theory .... and maybe one of them is even correct LOL. RTN in established colonies is tough to diagnose. As long a no parameters are totally out of whack, get the affected colony out as quickly as possible and chalk it up to bad karma.

 

[KrisReef]

Everyone will have their 'pet' theory .... and maybe one of them is even correct LOL. RTN in established colonies is tough to diagnose. As long a no parameters are totally out of whack, get the affected colony out as quickly as possible and chalk it up to bad karma.

Yes- one new Pet theory to attempt resolution of the mystery in hopes of avoiding a repeat:
Water flow & circulation? You dose, (and ATO? ) Is the return Flow-aimed around the coral losses? The first coral to get hit if alk Spiked or fresh water flooded the sump could be expected at the return nozzle intersection.

heater malfunction, salt creep avalanche, chemical additives mentioned for your consideration.
Sad to see this happen to your tank,
Maybe they Just have gotten old like me?

 

[schuby]

What's the time difference between the two pics? There are several large, new colonies of corals in the second pic, and there's missing corals, too. Hard to believe they were all added and removed in just 12 hours. I'd classify the change in corals as significant. Did your Alk consumption change a lot between the two pics?

I have a few other questions. Do you have a lot of fish? What levels do you keep your phosphate and nitrate at? I'm curious to know if you have a high flow of nutrients in and out, or a low flow of nutrients.

 

[hometown9]

Yes- one new Pet theory to attempt resolution of the mystery in hopes of avoiding a repeat:
Water flow & circulation? You dose, (and ATO? ) Is the return Flow-aimed around the coral losses? The first coral to get hit if alk Spiked or fresh water flooded the sump could be expected at the return nozzle intersection.

heater malfunction, salt creep avalanche, chemical additives mentioned for your consideration.
Sad to see this happen to your tank,
Maybe they Just have gotten old like me?

Given I work from home now, and sit right next to the tank, I monitor it pretty much every waking hour. I've had some of the issues you describe above over the years (broken ATO which led to freshwater infusion, overdoing, underdosing, flow changes), but in this case I can say absolutely nothing changed (other than the corals touching each other). Now maybe something is leeching that I'm unaware of, but I would think it would affect more than the three that were lost. So far haven't seen any other indication of decline across rest of the tank.

 

[hometown9]

What's the time difference between the two pics? There are several large, new colonies of corals in the second pic, and there's missing corals, too. Hard to believe they were all added and removed in just 12 hours. I'd classify the change in corals as significant. Did your Alk consumption change a lot between the two pics?

I have a few other questions. Do you have a lot of fish? What levels do you keep your phosphate and nitrate at? I'm curious to know if you have a high flow of nutrients in and out, or a low flow of nutrients.

The healthy pic is from a few months back, but that was the most recent one I had taken prior to the loss. I woke up last Friday, everything was fine. By noon the RTN had begun. By evening everything was gone across all 3 pieces (which had grown into each other btw over the 3 months).

Have 6 fish in an 80 gallon. PO4 @ .05; NO3 @ 2-2.5. feed 3x week - reefroids, phytofeast, frozen.

 

[ScottB]

Another suggestion (you asked) would be to ship out an ICP test. Whenever I cannot explain a mortality I tend to do it. Been a long time since it actually explained anything, but it rules OUT a lot. You will either sleep a little better or make some correction. Either result is a win.

Another dead acro thread bouncing right now tested with copper.

 

[hometown9]

Another suggestion (you asked) would be to ship out an ICP test. Whenever I cannot explain a mortality I tend to do it. Been a long time since it actually explained anything, but it rules OUT a lot. You will either sleep a little better or make some correction. Either result is a win.

Another dead acro thread bouncing right now tested with copper.

Sure will give it a go. Last ICP test came back a few months ago clean but like covid tests, they can come back favorable and a day later the entire situation could have changed. What's odd here is the three acros that bleached were all touching and all expelled their algae in 12 hrs. So far nothing else has been affected, even one that is about 1cm from the colony that was affected.

 

[ScottB]

Sure will give it a go. Last ICP test came back a few months ago clean but like covid tests, they can come back favorable and a day later the entire situation could have changed. What's odd here is the three acros that bleached were all touching and all expelled their algae in 12 hrs. So far nothing else has been affected, even one that is about 1cm from the colony that was affected.

Sorry but best I got. Just on the odd chance it is the canary in the coal mine. IME the vast majority of these random deaths I am not able to explain but I always want to know I don't have a larger, systemic issue that would keep me awake.

 

[KrisReef]

Reread the posts and three catastrophic colony failures in close proximity would suggest that something was going on inside the tank that made living for corals at that location no longer possible. That coral have been growing well there before this time, and with measured parameters not observed to be spiking, tanking, or swinging what could have made this portion of the reef die?

And ICP should be helpful to rule if something elementally was wrong. Too much rapid coral death at one short time to have been known coral pests but perhaps the fast growth in the tank and close proximity of many coral colonies led to biochemical warfare to break out amongst the inhabitants in the tank? Being right in the top and middle of the tank may have not been the best place to be when something like that was going on?

An ICP test may help eliminate a lot of these questions.

 

[Greengny]

I wouldn’t glue over the base that has spread out. I had a large (3inch) frag RTN. It looked like the base was also lost. But 20-40 days later it regained its color and is now growing fine.