green algae

[famman]

my cory tank 20 gal high, ph7.6 gh6 kh4 eheim2213, lightly planted with /cf light.
6 corys 5 otos 2 danios 1 neon
what's the usual way to get rid of it? (other than scrubbing)
it's definately not brown algae, it's green and mostly on the walls but some on some small rocks.
Am I overfeeding? Too much light? Can I blackout it away at least for a while?
any help appreciated.
:)

[Dabbler II]

Blacking out a tank works well on the "green Water" from free floating algae. But if it is growing on the tank glass or rocks you have to clean it off. There is an imbalance in some nutrunt(sp) in your water. You (imo) will always get some algae growing in your tank I have to clean the glass in mine every week but thats the only place it forms. Wetman will prob have an idea. How much light is it (watts?):D