Brown thing on bubble coral

[TinFury]

Can anyone tell me what this brown stuff is? It's been on my green bubble coral since I got it and I have no idea what it is. I really need some input on how to get rid of it.

[amcarrig]

Looks like zooxanthellae to me...not much you can do about it if it is.

[TinFury]

You mean the symbiotic zooxanthellae? The thing that gives it it's green color? Then why would it turn brown?

[Tangster]

Light K value and intensity and photo duration all of these will make them turn off to another color. Like a tan..

[TinFury]

Maybe too much light then huh? Can too little light turn it brown as well?

[coral reefer]

I think that you don't have enough water flow causing microalgae to form on the bubbles of your Plerogyra! The vesicles of your Bubble coral will adjust to the available amount of light in your tank.
The other thing that i can think of is maybe your bubble is bleaching, therefore losing the zooxanthellae in its tissue, causing your bubble to whiten in color.

[amcarrig]

Originally Posted by TinFury

Maybe too much light then huh? Can too little light turn it brown as well?

No. Too much light would be the culprit in this case. I have never seen micro algaes grow on a healthy coral regardless of water flow. Just doesn't happen.