My aquarium water nitrate levels have usually ranged from 2-5 ppm, after I started an every other day 30-40% water change routine, so unless an aquarists lives in a high nitrate area , high nitrates coming from the tap is a bit of a stretch. In the U.S. the MCL (maximum contaminant level) for drinking water is 10ppm, any water provider would be severely reprimanded (fined) for exceeding it.
The only place I could see in the U.S. going over would be someones private well in a rural area.
I almost always used certified drinking water test kits, with results into the 100th place, "but" more than the test kits being unreliable, are the techniques and lack of rinsing when aquarists do tests.
When dealing with tiny amounts of water 10mls or less, and parts per million. even a tiny spec of residual left over in a tube can skew results.
This is why I always rinse test tubes at least 3 times with DI water during testing, upend them to air dry when done.
The only place I could see in the U.S. going over would be someones private well in a rural area.
I almost always used certified drinking water test kits, with results into the 100th place, "but" more than the test kits being unreliable, are the techniques and lack of rinsing when aquarists do tests.
When dealing with tiny amounts of water 10mls or less, and parts per million. even a tiny spec of residual left over in a tube can skew results.
This is why I always rinse test tubes at least 3 times with DI water during testing, upend them to air dry when done.
