Glass like balls growing on my live rock???

[Richard]

I'v noticed glass like black/silver balls growing on my live rock in the past few months. Anyone know what these could be?

[jamal-188]

Any pics?

[reefrunner69]

Sounds like Valonia sp bubble algae. Considered to be a pest algae as it will encroach on sessile inverts.

[reefobsessed]

Are these the green glass balls?? If so, I am also getting over run. How do you get rid of them??

[loganj]

What kind of water are you using? Are you running a skimmer? Valonia usually indicates a high nutrient level. You can pick the bubbles off with tweezers. Try not to burst any of them as thousands of spores are released when you do. Are you seeing any cyano or hair algae? It has been said that emerald crabs will eat valonia, but mine apparently feel that such common fare is beneath their dignity...they won't touch it.

[NaH2O]

If it is possible to remove the piece of rock they are attached to and pull the bubble algae off with tweezers, pinching at the base where they are attached to the rock. You can also try using your fingers, but tweezers work better, IMO.

[cybercron]

My tank has several green balls growing in various places. My LFS called it grape algae and said they were harmless. In fact I just purchased a piece of rock with some polyps on it and there were several green "grape" algae colonies. If this is not a beneficial algae please let me know. My LFS could be wrong!

[reefrunner69]

Need a pic, but IME, if it is grape caulerpa OR bubble algae...it is a pest.

[NaH2O]

cybercron, your LFS may have thought you have grape caulerpa. There is a difference. Check out the following links I have posted.
>>Grape Caulerpa Algae Pic<<

>>Bubble Algae Pic<<

>>Valonia species Algae<<

[loganj]

Hey Kevin,
Won't tangs eat the grape caulerpa?

[tims]

if ti is grape caulerpa, then put it in your refuge tank if you have one.
if it is bubble algae you can scrup the rock off out side of the tank.also can get some emeral crabs and a few types of shrimp will go after it. not sure which ones (shrimp that is). a pair of crabs should take care of the problem.

[Richard]

Thanks for the info, I have the Bubble type, I think they look cool and after reading your attached article I think I will leave them alone. They started growing after I added a Metal Halide light to my tank.