Coral slowly bleaching

[tphan]

I have this coral that has been in my tank for the past 2 months. Two weeks ago, it starts to bleach in the underside of one of the branch. Now it is speading to others branches. However, the affected areas are always the branches undersides. Is this because there is not enough light or something else?

Specs:
55 gallons tank with an additional 20 gallons refugium
8.22 ph
79 degree
0 Nitrate
250 Watt 20 K MH with 4 65W PC (2-actinic + 2-10k )

This tank has been running for 9 months.

 

[myreeef]

Is it just loosing it's color? or is it shedding it's skin?

If it is shedding it's skin, I would take it out and frag the unaffected branches right away. Make sure that where you cut the new frags is well above the infected/affected areas. Otherwise you could loose the entire frag/colony in a very short period of time.

You can use a dremel or some cutters or even a hammer and chisel to frag it with. Try not to touch it with your hands. Frag it in a separate bowl with your tank water and rince it with your tank water after cutting. Don't reuse the bowl of water or the rince water.

If it is just loosing color, it could be temperature, lighting, water flow, salinity, irritation,... no need to frag, just find a happier place in your tank for it.

Good luck, I hope it survives.

 

[Len]

It doesn't look like bleaching to me, but rather tissue recession. It would appear that your Acropora isn't getting enough light and/or current around the base. Increasing both is a good idea. If the recession is slow, then it might not be a pathological bacterial infection. Increasing the flow and light should do the trick. Make sure you Ca and alkanity are good as well.

 

[RUCoralGuy]

Yea, I've had similar problem with my Acropora microthalamus. Seems like once the colony gets to big the lower portion of branches start to bleach. I haven't seen any necrosis, but what I've done is frag the colony above the bleaching. I don't think many of you have tried this since i'm assuming most of your corals are for display, but since my coral are for research and my job is just to propagate as much as i can, hanging coral from fishing wire seems to help alot with this bleaching Acropora problem. If bleaching continues after I frag, I'll frag again and hang the pieces and they usually (8 outta 10) do better.
good luck!

 

[Anonymous]

What about cooling those temperatures, too? I really like to keep systems cooler than many others, but have always had good results. Bleaching is seen in wild settings when the temperatures get too warm, and who knows, it may help.

 

[tphan]

Thanks all for your advice. The coral base appears to be fine. The CA level is at 400. I was hoping to not frag it because it is the center piece of my tank. Oh well. Guess I better start the operation now.