Keep your eyes open for a few Otocinclus Catfish and/or some True Siamese Algae Eater's (Crossocheilus siamensis). I've got 1 true siamensis and 4 oto's in a 30G that had tons of brown crap growing on the plants for a bit due to a phosphate buildup. I've been treating the phosphates while the oto's and true siamensis have been cleaning up the plants nicely with no harm.
Find the source of your algae, whether it be phosphates or something else natural with a new aquarium or insufficent light, and fix that if you can. The fish mentioned above should help clean the existing algae. The oto's are quite entertaining as well, especially in groups of 3 or more.
What's your lighting situation like (hours on, wattage)? Is the tank an established one, or is it new? Have you tested for phosphates at all?
Colin