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Need help: RTN rapid tissue necrosis


IUnknown

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My Acropora looks like it has rapid tissue necrosis. Or maybe its just bleaching, but I haven't seen a good picture of bleaching to ID it as so. Do you guys recommend that I break off what is left and healthy, frag it, and discard the rest? I don't know if this thing will make through tomorrow. I think big temperature swings and changes in light duration was the cause. The Chalice has the same thing, but I don't know if I can do anything. I have iodine dip coming in the mail, but don't think it will make it in time. Thanks for the help.

 

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lakshwadeep

the acro is definitely showing RTN. You can tell by the flesh sloughing off and leaving a white skeleton.

 

How long have you had the corals, and where did you get them?

What are the water parameters?

Anything recently added?

Anything missing/dead?

What exactly were the " big temperature swings and changes in light duration"?

 

I don't know much about chalices, but it seems odd it would also have tissue necrosis. This sounds like a general problem.

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I ended up fragging the coral and throwing out the dead parts on a recommendation from another board.

 

How long have you had the corals, and where did you get them?

Live aquaria. Just got the Acropora last week. The chalice I've had for about a month.

What are the water parameters?

7.15.09

salinity=1.0255

temp=79.3 @ 6pm

ph=8.2@6pm

kh=116-120 = 6.7 dkh

NH3,N02=0

No3<1

 

Need to get a test kit if I'm going to measure hardness or P04. I'll look into getting a two part additive this weekend, since from what I read the alkalinity is a little low (even with 20% water changes a week). Any recommendations?

Anything recently added?

This was a second batch added to a tank that has been running for 3 months. After reading more about Acropora's, I'm realizing that might have been premature.

Anything missing/dead?

Nope. ORP monitor is in the mail so that might help later.

What exactly were the " big temperature swings and changes in light duration"?

I think this was probably the culprit. Temp swings from 76-82.4. I need to check and calibrate the digital thermometer. And from what I've been reading, anything more than 5 degree swing stresses corals. MH went from 8 hours to 11 hours. That was my dumb mistake. I don't know what I was thinking. :huh:

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lakshwadeep

You also need a calcium test kit if you keep stony corals, especially sps. Yes, alkalinity is lower than the normal range:

2.5 - 4 meq/L or 7 - 11 dKH or 125 - 200 ppm CaCO3 equivalents

http://www.advancedaquarist.com/issues/nov2002/chem.htm

(to convert dKH or ppm CaCO3 to meq/L, divide by the dKH value 2.8 or the CaCO3 value by 50)

 

Other things look okay. A two-part additive like b-ionic is a great idea.

 

However, temperature was probably an influence (a non-functioning heater killed off many of my first acro frags). Get a glass "analog" thermometer as a reference. What was model/brand was the digital thermometer.

 

Also, many people have reported good success with photoperiods less than 8 hours (some as little as 4), so that's something to keep in mind.

 

Two other points:

Your Acro looks like a mini-colony or larger instead of a frag. Colonies often have grown in a set lighting/flow condition for a long time, and they often have trouble adjusting to a new tank. Frags make cheaper and more manageable options, even if it will take longer for them to reach the same size.

 

Also, was the frag from the "maricultured" section of liveaquaria? Those are corals that have been grown in the ocean, and they have a higher chance at not adapting to captive tanks than aquacultured individuals. Chances are that a frag from a local owner or other aquaculture facilities will be more suited to captive tanks (and often more colorful, too).

 

In many cases, it's hard to stop RTN once it has started, so be prepared to remove the entire colony if it keeps getting worse.

 

Finally, I worry that the SPS may have been stung by the LPS at the bottom left of the first photo. It may seem far, but some LPS have long sweeper tentacles.

 

In the future, if you're getting your first SPS, I suggest starting out with Seriatopora (birdsnest) or Pocillopora species. These SPS are some of the first stony corals to colonize new reefs, and they offer more room for error.

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I'll check on the calcium tonight (I think I have a test kit in the garage). And I'll grab some b-ionic this weekend. The thermometer is a "Lifegard Aquatics Little Time or Temp"

http://www.drsfostersmith.com/product/prod...amp;pcatid=3894

The corals were from the Diver's Den section on liveaquaria. I don't think those are maricultured? Those are good points though, thanks.

http://www.liveaquaria.com/diversden/index.cfm

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So I'm going to start reading up on two-part dosing. Anyone have any good links or resources. Is b-ionic the more popular way to go? 20 gallon tank.

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So looks like the tank is crashing. I lost half the SPS frags and the rest of my SPS have started getting RTN. I measured the KH again but I think my test kit is wrong, so I ordered a new one. It was saying that the reef crystals was at 52 ppm? I did buy a Ca test kit today and the tank and mixed water are both 300 ppm. I guess I have a bad batch of reef crystals? I sent them an email to see if they will send out a new bucket. Measured the phosphate and its .05 mg/L. Talk about feeling crappy.

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did the water change. The only other thing I can think of, I replaced two 24w t5 bulbs around the time this started happening. I had two really old 6500K bulbs from my planted tank days and then upgraded to antinic and blue bulbs. Could something that minor do any damage? I turned them off for now to see if it does anything.

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