I have a 29 gallon freshwater community tank. I have noticed that there are "green spots" growing on the tank walls. They are about the size of pin heads. They are easy to scrape off with some type of sharp object but an ordinary algae pad won't remove it. I know it has to be some type of algae. Can anyone tell me what it could be? My live plants have it as well!!!

Might be hairline Algae. If you don't like scrapping it off, than cut down on how much food you feed your fish, and don't leave the aquarium lights on so long. Don't give them a chance to live. Live plants may also help, by giving competion for the nutrients. Hope I helped. Keep us posted.

-Ross

Have you tried a credit card to remove the algae?

Oh I have no problem removing it. it just can't be removed with an ordinary algae pad. I also have plenty of live plants as well.

a few otto's might clear that up. They love to grave on algea from plants. Consider it, unless you don't mind scrubbing...

-Ross

The green algae is not my favorite at all. The light and plants combined
make the algae grow. I couldn't remove it with a algae pad, and my plecos
ignore it so it is more work to remove.

plants actually make it grow slower.

but i like the credit card idea

Yeah, live plants help to give the algea competition for nutrients, so it will make it grow slower, if at all. But still consider the otto's. They stay small, and like to eat all kinds of algea, especially off live plants.

-Ross

My tank is definatly messed up then. Green algae only grows in my tank with live plants.

Maybe! But then again, you might have red algea, and, apposed to it's name, it isn't always red. It does grow alongside plants quite frequently.

-Ross

I was thinking that, but it is not red algae. I've had that before and remember what it looked like.

Oh, I don't have a clue then..sorry!

-Ross

I'll call it, Mystery Algae of the shallows!

Mystery Algea of the Shallows it is then.

-Ross

lol, I should get it published!