Have had ZERO nitrates and phosphates for months. Have tested freshly made water as well, same results, zero.
I've found that many salt brands are inconsistent at some point as I've personally tested Oceanic salt (been a while) and found it to contain high levels (for salt mix) of nitrate and phosphate. Been unhappy, at some point or another, with reef crystals too.
Funny how most of us will cheap out with absolutely vital aspects of our tanks (salt and heaters). No problem spending hundreds on coral and fish though! Thinking of using E.S.V. B-Ionic...