most accurate nitrate test

[Delphinus]

I suggest probe as well, except factor in to the already steep purchase cost, the cost of a replacement probe is darn near the price of a whole new unit and I only got about 18 months on mine before it crapped out.

I find there's a lot of guessing with any of the colour based ones. I wish there were titration based ones like for Ca and Alk, but I guess the chemistry just isn't there for that.

I cycle between Elos and Salifert. I used to use Seachem, which I liked at the time because it came with a reference solution you could use to verify your interpretations.. however I haven't seen these for years now at any LFS I visit so I don't know if they exist anymore.