Rtn?

[Jim Tansey]

Just getting to post this now. I lost all my SPS corals except for the two larger polyp Millepora and a Pocillipora. Most had been in the tank 4-6 months and doing well. I purchased an orange Digitata at the 3/27 meeting, a couple of days later I noticed it was losing polyps around it's base; thinking it was from epoxying it to the rock I paid little attention. I then noticed my two orange Caps losing color, checked water conditions everything looked OK. I still had not connected the dots until all the small polyp SPS started looking bad and within a week to 10 days all were dead.

1. From the picture can it be determined it it's RTN?

2. Would a dip have prevented this? If so, what kind?

3. Why did it effect only the smaller polyp SPS?

4. How long before I can add more SPS?

Regards,
Jim

 

[Mike A]

Jim, I'm just taking a guess here, but I don't think what killed your corals
was rtn. Usually rtn will spread through a coral population like a forest fire,
turning your sps into white skeletons within a few days. Since you said it
was a week to 10 days, I'd look at another cause. From the pic, it appears
that the polyps are being overtaken by some type of microalgae. What water
conditions did you check ?

 

[Gumhead]

Yes please post your...
Alk, pH and Calcium levels

 

[Jim Tansey]

pH/Alkalinity, Nitrite, Phosphate, Calcium, Magnesium, & Specific Gravity.

 

[Jim Tansey]

11.2, 8.4, & 430

 

[Mike A]

Those params are all pretty darned good. Was there some other type of
stress or dramatic change in your setup recently ?

 

[Jim Tansey]

No everything looks good; fish, anemones, lps, softies, & other inverts.

 

[ScottM]

Jim, I'm just taking a guess here, but I don't think what killed your corals
was rtn. Usually rtn will spread through a coral population like a forest fire,
turning your sps into white skeletons within a few days.

i've had RTN wipe a colony out in a matter of hours.
its colored flesh just falling all and floating in the water.......

what are you using for top off? nitrates? salinity? temp? how old is the lighting?

 

[Jim Tansey]

RO/DI unit, 10 ppm, 1.026, 80-81, (2) 250W 10K Ushios, (2) 03 URI Actinics on a 75 Gallon, lighting new in Janurary.

The Digitata shown did have its colored flesh falling from it in string like form, most of my other SPS's the polyps are so small (Acros etc.) that all I noticed was a slower loss of color.

 

[Greg Hiller]

Jim,

That is really strange. I agree with the above comments, your parameters seem pretty good, and the lighting should be fine. Is there any chance that some critter is dining on these corals? Maybe some type of large worm or something? You might check at night. There is also a Montipora specific nudibranch that I have heard of. FWIW, in my limited experiences with RTN I found that the Montipora's were largely unaffected, it was the Acros and the Pocilliporas that were hard hit. I have heard of some people having problems with Montipora's in general with their tank, but I have a really hard time killing them, even when I want to!!

 

[Lam]

I was also thinking of montipora nudibranches, but I couldn't quite make out the linear tracks usually created by them. Do you remember a line of denuded tissue? Maybe someone with experience with them can make a more accurate determination based on that picture?

Is it my imagination or do you have quite a bit of green microalgae like Mike mentioned?

 

[Aquaman_68]

Don't think it was nudis that are the cause. Nudis don't cause flesh to peel they just gobble it up very neat like. It looks more like a deficiency of some kind. Did you post a value on your mag? Greg is on about some tanks having problems keeping monti's alive. In the begining of my reef hobby I do remember having problems keeping orange caps alive as well as orange digi's. The only think that I recall.........I was having issues with a low mag level. This was due to the salt I was using & water changes that were done. Not sure if that was the problem or just an immature system. Nevertheless....it is very hard to tell from the pic posted.

Ps. That ro unit looks like it may need something replaced. You should have 000 ppm product water from your unit if it is working & filtering properly. Specially if you intend to dabble in sps.

 

[Jim Tansey]

The DI is 0, I don't recall the Magnesium level but it was in a good range. I change 13 gal every two weeks, this happned to fast to be a decline in a trace element.