Green algae

[kreblak]

My tank is being consumed by a dark green algae. I had large quantities of brown algae, but my hermits and snails (along with some RO water) have wiped out that problem. Now, there is a patch of growth below the substrate surface where it meets the tank wall. It was the size of a quarter, and is now the area of a dollar bill. Plus, it has expanded above the substrate.

The algae is dark green in color, and sort of forms swirls on the glass (like a fingerprint almost). It seems to have hairs. The algae below the substrate appears to have air bubbles trapped in it. What is this algae? Is this the "bubble algae" I have seen posted about so many times? Why aren't my snails and hermits eating it, and how do I control it? Finally, is it a good thing that I have green algae growing in my tank... i.e. does it indicate a healthy ecosystem?

[OrionGirl]

I can say that is not the bubble algae you see posted--that kind of algae is actually small, individual balls of algae--looks like little green bouncy balls.

Is this stuff hard to the touch? Does it wipe away easily? If it comes away in sheets, and is velvet soft, it could be a form of cyano--not really algae, more of a bacteria. It's not really good or bad, but can get out of hand. http://www.wetwebmedia.com/greenalg.htm has some good pics to help identify, as well as some advice.

[kreblak]

Thanks Orion, that link led me to the information I needed. In case anyone cares, it turns out that I have green hair algae. Now if I can figure out why my inverts aren't chomping on it....

[Mandairn]

What inverts do u have?..

[kreblak]

Six red legged hermit crabs, one blue legged hermit crab, and four turbo snails.

[Mandairn]

try more blue legged hermits they chow on it.

[VoodooChild]

That doesn't sound too much like hair algae, due to the dark color, but you may want to take a look at a mythrax crab. I bought one a couple of weeks ago and he's really done a number on the hair algae and larger clumps of green. And he works all night and day!

[kreblak]

How big are mythrax crabs? I have heard that do an amazing job on bubble algae and other types of algae, but I wasn't sure if he'd work on hair algae. Also, do they eat only algae, or will they prey on other things in the tank like small fish or other inverts?

[VoodooChild]

If my little guy stretched out his legs he may measure out to around 1.75", but probably more around 1.5". He's the coolest thing in my tank. Looks like he's straight out of a sci-fi movie. And he's really cleaned up my rocks, so well I was thinking about getting another. There's more than he can handle. I think he's afraid of the fish, as he darts into his hole whenever someone swims by, but last week my royal gramma had a big chunk of skin missing from one side. It was more of a scrape than anything, no bleeding, and he's nearly recovered. The only thing it could be is either the mythrax or if the gramma scraped up against a rock. If it is the mythrax though, he's too good to get rid of. Besides, ime, once a fish associates something with pain it remembers and will stay away.