Innacurate test kit?

[Wolf89]

My api test kit says my nitrates are over 180, which I'm find hard to believe
It's a 90 gallon tank with a 40 gallon refugium/sump filled with chaeto
I've done 4 20% changes in the past week and this hasn't made a differnce
Plus, I have no algae, like at all. I clean the glass every week, if that. No other algae at all. Is it reasonable to assume the test kit is wildly inaccurate?

 

[homer1475]

API, yes.

 

[lapin]

If you look at the BRS boys video there might be a reason they did not test the API kit