Green Spot Algae

[jfox]

Anyone know what causes it, low light? high light? nitrates?

How to get rid of it?  I've been using the credit card method. (thanks Dave)

Thanks in advance!

[BigDaddy]

Just about every planted tank gets it.

How big is your tank?  What kind of lighting do you have over it?  What fertilizers are you using, and if so, how often and how much?  Are you using CO2?

Give us the big picture... and we can probably come up with an educated guess    :lol:

[jfox]

65gal long tank with 2X 4' 40W aqarium lights.  I use Hagen fertilizer, plant grow.  I use half the recommended dose.  I only have three small amazon swords.  I do not have CO2.

Hope this helps.

[BigDaddy]

I would avoid using the liquid ferts altogether in that setup and simply go with root tabs.

The swords are heavy root feeders anyway, and with no ferts in the water column, green spot will not be an issue.

PS - How are the swords holding up under that lighting?  Seems like it might not be quite enough for them.

[jfox]

The swords aren't growing fast but they're not hurting either.

[gvv]

"Spot algae:
Grows in thin, hard, circular, bright green spots, usually on the aquarium glass but also on plants under high light conditions. Considered normal for planted tanks. Must be mechanically removed. On acrylic aquariums, use a cloth pad or a gentle scouring pad like a cosmetic "Buff-Puff" and a lot of elbow grease. On glass tanks, scraping with a razor blade is most effective. "

Here is the source: http://www.plantgeek.net/article_viewer.php?id=9