Nitrate vs total Nitrogen

Has anyone ever been told that liquid Nitrate test kits actually measure total nitrogen?

Was at a different LFS recently and told the saltwater manager of my problems getting Nitrates below 25 even with relatively low bio-load (2 juvenile perculas, 6 line wrasse and juvenile flame angel in a RSM 250 approx. 50 gal total). He asked what brand test we are using (Serra) and said we were getting total Nitrogen not Nitrates and suggested I use a powder based test, specifically Instant Ocean. We bought the Instant Ocean test and sure enough it reads <10 Nitrates; in fact the test water was essentially colorless following the instructions of the new test.

I am REALLY hoping he's right as the Nitrate levels have driven me close to insanity the past few months....ok I was really close to insane without the Nitrate situation, Ha!!

Anyone agree/disagree? I called and asked if I should be concerned with high Nitrogen, he tells me it matters not at all.

 

If that was total nitrogen would that mean you had a combined total of 15ppm of nitrite and ammonia???? That doesn't make sense. Other than that the pure nitrogen (N) in the tank is gas. Like the bubbles in the sand bed.

*i think*



Edit: 300th post!!! TO GLORY!!!!

 

that's what i was thinking..do they mean ammonia/nitrite too? if they do then it really shouldn't matter as they should be zero..then the only thing left should be nitrate..