Actually, that might help. It is something I have never thought about, but both of the low light tanks that I have my java ferns in both have high nitrates, because there aren't a lot of fast growing plants to suck it up. The range is around 30PPM in both of those tanks. It could just be that as luck would have it for me, the tanks that I wanted them to grow in just happen to have ideal conditions for them.
Two 1 GA desktops, a 5 gallon, a 2.5 gallon, a 10 gallon, a 20 gallon, a 25 gallon, and two 75 gallon tanks, all planted.
I am an expert on algae, so ask me if you have questions. I know how to grow it, just not how to get rid of it.