What's the point of removing nitrates from a planted tank? Plants do that for you on their own. If your nitrates aren't being removed by your plants then you are way overstocked with fish or understocked with plants (or something else is missing).
Plants need nitrogen in some form to grow and can't take it directly from air as N2.
72g bowfront planted, CO2, 4x - T5HO, Eheim 2213 and 2217, 2 angels, pristella tetras, blue tetras, betta, albino bristlenose pleco, albino cories. Sword, vals, hygros, ludwigias, java moss and fern, anubias
2g Mac-quarium. Clown gravel, fluorescent plastic plants, and 2 guppies.