If the algae on the glass is brownish and you have some spare room in the tank, maybe consider a half dozen otocinclus- or even a clown pleco or bristlenose pleco. I got a clown a couple days ago, and despite most sources saying that they won't eat algae, it has started scraping off some diatoms. I also agree with floating either some anacharis or pennywort, pennywort won't work quite as well but looks a bit better in my opinion.