I Spoke w/ Water Company

[GIS Guy]

I just finished speaking with my local water company. We spoke about the nitrate levels in tap water. Yesterday I tested the water and it registered between 15 and 20 ppm. The water company performs daily tests and said they keep the nitrate down to about 7.5 ppm. If it raises to 10 ppm then they have to announce it to the public and perform a bunch of stuff that the company would rather not have to do. This leads me to believe that the test kit (Aquarium Pharmaceuticals, drops) is off by a factor of 5 to 10 ppm.

Has anyone else spoken with water producers about nitrates?
What about the accuracy of the test kit?

ALL Suggestions/Comments/Answers/Opinions are welcome. Thank you.

Edit: The information that I received from the water company shows that the dropper test is at minimum twice that of their tests. That is a 200% error (7.5 ppm water company to 15 ppm home test).

 

[wayne]

I'll give you a tip - in the only independant testing of nitrate test kits I have seen against a lab standard NONE of them were especially accurate. The AP kit was better than most, and certainly tracked trends, but frankly if you expect a coarse dropper test to measure with a colour chart nitrate to 1 ppm you are very, very hopeful/naive.

Use testkits to track trends, but be cynical with the numbers. Some are more reliable than others (pH, alk should be better) with ammonia, nitrate and most phosphate at the bottom of the pile, unless you want to use test kits coming in at 100$ apiece

 

[Lotus]

One thing I have noticed with the AP tests is that if you leave them for more than 5 mins, the readings go up. It also makes a difference in which light you view it. You will get the most accurate results in natural daylight.

Did you test distilled water as a control?

I don't usually assume the tests to be very accurate, but they at least give me a reading of none/low/medium/high to go by.