New and going for broke

[grinner30]

I have the rock in 2 30 gallon tanks with a power head in each, a heater and a air stone (becuase I was not sure if it needed it our not) I will be changing 5 gallons or so in each tank today.

1. Some of the rock seems to have green algae growing on it. Is that okay? Pic below

http://s994.photobucket.com/albums/af68/grinner30/?action=view&current=100_1824.jpg


http://i994.photobucket.com/albums/af68/grinner30/100_1823.jpg