I suggest you get plants, they look nice, oxygenate (sp?) the water, and they (from what I've read) turn ammonia into nitrite and nitrite into nitrate. Then you can simply change the water to get rid of the nitrate. If you get plants dont get the ones in plastic containers, the containers dont look good. One thing that I found was a good value is to get plant seeds. All you do is drop the seeds in and wait for them to sprout.
Good Luck with fish keeping!
Good Luck with fish keeping!