SPS turning white.

[JDigital]

My one and only SPS colony is starting to go white on me... down around the base.??

Is it a color change? or something else?

[OCDP]

Originally Posted by JDigital

My one and only SPS colony is starting to go white on me... down around the base.??

Is it a color change? or something else?

I'm no SPS expert, but have you done the usual checks? (calcium, alk, etc.) Is the white like skeleton white, or does there still appear to be tissue where it's going white on you? My only guess is some sort of STN/RTN??? We'll wait for the real SPS pro's to chime in....

Hopefully it's nothing serious and it bounces back for you.

[Chowder]

I would say something else like Rtn or Stn. Did it turn white over night? Did you notice the skin sluffing off? A picture of it would give us a better idea also some tank water params.

Chris

[Slick Fork]

are the polyps still extending?

[Delphinus]

Without a picture here's what it could be.

- Bleaching. "Bleaching" refers to tissue that turns white, but is otherwise "still there." It can lead into RTN, or STN, but sometimes can come back. It can be caused by many things including light shock, or shading. If the top of the coral shades the bottom, this can happen, but it's usually with larger colonies.
- RTN or rapid tissue necrosis. The coral looks white but it's not bleaching - it's the skeleton. The tissue itself is gone, melted. Many causes. More on this later.
- STN or slow tissue necrosis. Same as RTN but much slower recession. Again, many causes.

Bleached tissue can come back (no guarantees of course). With RTN and STN, it's gone. You have to address the cause and hope that there's enough coral for it to grow back. With RTN the coral is usually a total loss.

Ok, causes. Ultimately, it's a reaction to stress. This could be low Alk, excessively high Alk, low Ca, excessively high Ca, Ca/Alk out of balance, presence of NO3, presence of PO4. Can also be allelopathy (chemical warfare), not enough light, too much light, too hot, too cold, too much temperature swing between day and night, too much pH swing, fish that nip, crabs or other inverts that nip, moon phases, you looked at it wrong and whether the day of the week it is currently ends in "y". (Welcome to the wonderful world of SPS. ) Sorry I realize this isn't helpful but the problem is SPS are like the canary in a mine sometimes. And although some are really hardy and can weather things, others are not so much.

Edit: I forgot to mention that sometimes RTN is protozoan in nature - meaning it's a parasitic infection of an organism. And likely contagious. This is a risk with wild-collected SPS.

One thing that we can likely rule out at this point is "excessively high Alk". For one, unless you're dosing without testing, the likelihood of this is low to begin with. But also, "alkalinity burn" tends to be more systemic in nature and literally looks like the coral is burnt.

SPS are a tricky mistress. I like to think of them this way: there really is no such thing as "stasis" or "stability". Ie., they are either growing or receding. So you pretty much need to stack the odds in the favour of growth and that is through good lighting, good water flow, low-to-zero NO3, zero PO4, good Ca and Alk numbers (either through dosing or reactors).

[JDigital]

No polyp extension... I haven't had PE since bringing it home actually..

I will run a few test kits, but things should be in line, water change was done on monday (remember this is a 20G nano)... I change it every week 10-15% with Aquamedic Salt.I've got a birdsnest in the same tank, and it is growing like a weed. And a 3 0.5" SPS frags that are holding their color. No PE tho.

Lighting is 175MH... Tank does get a bit warm in the day.. 29-30.. drops to 27 at night w/ a heater. Planning to add fans shortly..

couple pics.

[OCDP]

N/M . SPS Experts to the resscuueeee

Did you recently change lighting on this tank?

[Jason McK]

that is a clasic RTN. I would frag what you can and move it to the opposite end of the tank.

J

[christyf5]

Thats tissue necrosis, you can see it more clearly in the second shot. Not much you can do really other than either watch it closely or try to frag it and perhaps crazy glue the affected bits at the bottom to try to seal the tissue. It sort of looks like the tissue is thinning at bit at the top of the colony as well as the tips look like they've got some algae on them perhaps due to rubbing the sides of the transport bag or something.

Is it a new addition? You've had it awhile? It does look a bit "rough".

I'd put it down as low as you can in the tank in some medium flow area. Hopefully it will recover.

Good luck

[Delphinus]

Yeah, have to say it doesn't look good. Sorry. You can try fragging it as suggested.

Pretty much though for me once they get to that point they are as good as already gone. Your mileage may vary though, good luck.