Originally Posted by exv152
Matrix is the best de-nitrifying bio media. If you have high NO3 it's probably a good idea, but so are water changes. Whatever gets your planted tank NO3 spec to around 20ppm is good; be it substratpro, lava rock, micromec etc.
I just want to make sure that you meant denitrification in your post.
How is this media achieving localized anaerobic spots within a filter with so much water movement?