Sensitivity of API's ammonia test kit

[seabass]

OK, a couple more pics.  These are from a tub of cycling rocks, which I dosed to 2 ppm of ammonia two days ago.  However, there is no other ammonia source in the tub.  This gives a pretty clear picture of what undetectable ammonia looks like on an API kit:

 

 

[Thrassian Atoll]

That right there is a perfect zero color.

[seabass]

I agree.  That's why I say it's sensitive as opposed to giving false positives.  If I were to recommend anything to API, it would be to add a 0.10 ppm color bar on the chart.  I think that would satisfy most of the critics.

[Suzi]

My api shows .25 ppm even on distilled water! I have tried all 4 of my tanks, tap water, ro water and distilled. Always looks like .25. my tanks are 1 year old, 9 months 6 months and 3 months.  I have replaced my kit twice. I have 0 trites, anywhere from 0 to 40 trates, average of 7.2 ph considering all 4 tanks, 1 10g, 2 30g, and 1 40 long.  

[seabass]

Can you show us a pic of the tube, next to the color chart, taken under natural light?  It's probably nothing to worry about.

[Clown79]

On 2/9/2020 at 6:22 PM, Suzi said:

My api shows .25 ppm even on distilled water! I have tried all 4 of my tanks, tap water, ro water and distilled. Always looks like .25. my tanks are 1 year old, 9 months 6 months and 3 months.  I have replaced my kit twice. I have 0 trites, anywhere from 0 to 40 trates, average of 7.2 ph considering all 4 tanks, 1 10g, 2 30g, and 1 40 long.  

Are you checking the tube against the white part of the card in natural light?