According to this article, you can take steps to soften the water, lower the pH or get yourself some fish that eat algae. The first link in my earlier post gives more information about the causes and what to do. Apparently, brush algae is a bit tougher to eliminate than some. Doing a search on "freshwater aquarium brush algae" or "remove brush algae aquarium" will pull up a variety of articles such as those below. Most of the info is about 1/2 way down on the pages. Hopefully, you will come across a solution that is useful to you or one that is appropriate for your tank. Try performing a search on the forums here from the menu bar above and you will find information from others who have had the same problem and what they did to correct it. Good luck.
http://www.thetropicaltank.co.uk/algae.htm#brush
Scroll down on this one and you'll find the details.
http://www.aquaticscape.com/articles/algae.htm
Other options are described here:
http://www.thekrib.com/Plants/Algae/brush-algae.html
More info here.. specifically about phosphates and brush algae problems.
http://www.everythingfishy.com/algae.html