Algae isn't a bad thing. It's a sign of a healthy tank. Not much help though, right? I'd scrape it from the front of the tank, so you can see inside, but leave it on the other sides. Algae lives on nutrients, so you must have more than are being eaten by everything else in the tank. So, large, frequent water changes are needed. Change half the water every week or so to remove added nutrients.
I got some Ramshorn snails from the pet store, when I had algae problems. These little guys work wonders and they don't bother healthy plants. Time, the water changes and the snails should help.
Just some easy things that worked for me.
"Fear not, my young apprentice. Just change the tank water."