problem with Acropara coral

[AmosUSA]

Last night, I noticed some tips of my Acropora noblis coral died. All other species of corals and livestock in the tank (SPS, LPS, Soft, clams) are doing just fine.

All of my water parameters are good. There haven't been any changes to the system (lighting, filtration, etc.) recently.
For the past couple months, it was growing well, with several new branches visible, however yesterday, there was evidence of bare skeleton on the tips.

I did a 40% water change with NSW as a preventive measure yesterday, but the chemistry doesnt seem off. I run T5 bulbs over the system, with the same bulbs acitive for approximatly a year now.

I have looked for parasites and bugs but couldn't see any. Does anybody know what could have triggers such substantial instant recession of the tissue?

Thanks,

[Frick-n-Frags]

How long has it been in the tank?

I have seen about a one month period for a coral to finish dying from the day it was put in.

If this thing has been around for some good several months, you probably are having a water chem parameter shift or maybe the coral is malnutritioned<-although usually sickly corals die from the bottom up. damaged/burned corals die at the tips

it could also be a canary in a coal mine as the first to go down from a major problem. How's your longterm tank maintenance been?

year old t-5's need replacing??

[AmosUSA]

It has been there for a couple of years. After reading your responce i now know what i did i had a high calcium level mantaned in my tank. I got a little distracted from work and i let the calcium level go down and i think thats what has happened Question shuold i get the calcium up slowly back up to 500 wear i had it. or get it back up there quicly ? thanks for your answer it has help me out alot thank you.

[surfjeepzx]

"I run T5 bulbs over the system, with the same bulbs acitive for approximatly a year now."

Get new bulbs. T-5's and VHO's are only good for a year max and you really should be looking for new bulbs at about 11 months.

I've seen this in my tank before and a new set of bulbs fixed everything.

[sixliner6]

Maybe it's growth?

[mistergerardob]

T 5 last longer than a year, if the problem was the light your another corals should show some damage too. You can change your bulbs just to be sure.
Like you said maybe you calcium has something to do with it. Did you check you temperature? The other day in Indiana the temperature hit 80, my aquarium temperature when from 79 to 85, and my sps started to look funny.

[mushumatt]

Maybe you should ask in the SPS forum? Are you having any temp flucuations or such

[Frick-n-Frags]

I would jack Ca up to 380(min350) with calcium chloride in one shot for damage control, then maybe ease it up from there over a bit longer period of time because that isn't critical anymore.

well here's to hoping that does the trick []3

if the acro gets happy again, it will re-cover those ends in no time.

[Salamander]

What does "parameters are fine" mean?

That gives us little info to help you with. Please list your readings and it also helps to list the kit you test with.

I'm wondering what your ALK is? If your CA is screwy Alk likely is too.

ALK can have a big affect on SPS. I've seen improper levels kill the tips of Acros.

As long as algae doesn't take over the bare tips the acro should grow over it. If algae does take over, clip the tips off.

[atvdave]

<a href=showthread.php?s=&postid=9607443#post9607443 target=_blank>Originally posted</a> by AmosUSA
there was evidence of bare skeleton on the tips.

Are the tips turning white?

If so it's more than likely your flow in your tank. I also have some Acropara coral and my tips where turning white also. I got some new power heads and moved then to a new location and they started getting there color back..

Just something to look into.

[AmosUSA]

Hi everyone I vary much appreciate everyone helping out with this problem . I have been so concerned about what has happened. Well here is more data that may help. I have checked my water perimeter and my ammonia, nitrite, nitrate , phosphate, levels are undetectable my calcium level is 490 ppm and my ph 8.3 alkalinity looks good. I thought it was my calcium being low, I don't think it is because all my other corals are growing well. I had some one suggest to me that it does not look like bleaching, because the corals are not fading away there dying over night. My coral is loosing tissue from the bottom up . I was told from some one that it looks like I have something called RTN Rapid tissue necrosis so I broke off the bottom of the coral that died and placed the remaining branch of coral back. So everything looks good so far. I hope not to see anymore of this coral dying from the bottom up Can anyone tell me more about this RTN symptom that I was told about.