may nitrates ang stock water mo? why? kung saltmix ka, i'm almost certain zero yan. kung sa cartimar/kathrina's ka bibili, zero rin yun. san ka ba kumukuha ng water na may nitrates? save time and effort. magsaltmix ka o magkathrina's. use the denitrator on your main tank instead.
anyways, i use sulfur denitrator. check out our DIY thread for details