Heads Up. Nitrate Test

[gwand]

My API nitrate liquid test consistently reads a nitrate level of 20ppm for my well water. My tank water also reads 20 ppm because they are well cycled and I do frequent water exchanges. Twenty ppm is not safe for drinking water so I sent water samples to two independent certified water testing labs. One lab gave me a nitrate reading of 8 ppm and the other a reading of 9 ppm. API liquid nitrate test reads high, at least at low values.

 

[Uberhoust]

To be honest I would prefer it to read high I had a Fluval Nitrate test kit that consistently read low all the time. I was unsure about nitrates at that time that I made a reference solution and tested the API and Fluval kits using various Nitrate levels. Discussion about this is here https://www.fishforums.net/threads/nitrate-test-assessment.468948/.

 

[10 Tanks]

Hello. The EPA sets nitrate at 10 ppm in public drinking water. I imagine that individual states have something to say about the level too.

10

 

[Essjay]

For information, the American EPA uses the unit of measurement nitrate-N. Our test kits use the unit nitrate-NO3. 10 ppm on the nitrate-N scale (the EPA upper limit) is the same as 44 ppm with our test kits. So Gwand's 20 ppm using an API tester is the same as 4.5 ppm on the EPA's scale, well below the upper limit.



Other countries, for example the UK, use the nitrate-NO3 scale so our test kits use the same scale as the UK's DWI and we can compare our tank levels directly without having to convert the numbers.

 

[gwand]

For information, the American EPA uses the unit of measurement nitrate-N. Our test kits use the unit nitrate-NO3. 10 ppm on the nitrate-N scale (the EPA upper limit) is the same as 44 ppm with our test kits. So Gwand's 20 ppm using an API tester is the same as 4.5 ppm on the EPA's scale, well below the upper limit.



Other countries, for example the UK, use the nitrate-NO3 scale so our test kits use the same scale as the UK's DWI and we can compare our tank levels directly without having to convert the numbers.

Well that explains a lot. No pun intended. (I was measuring our well water). Thanks Essjay.

 

[gwand]

For information, the American EPA uses the unit of measurement nitrate-N. Our test kits use the unit nitrate-NO3. 10 ppm on the nitrate-N scale (the EPA upper limit) is the same as 44 ppm with our test kits. So Gwand's 20 ppm using an API tester is the same as 4.5 ppm on the EPA's scale, well below the upper limit.



Other countries, for example the UK, use the nitrate-NO3 scale so our test kits use the same scale as the UK's DWI and we can compare our tank levels directly without having to convert the numbers.

So the API nitrate kit is using the nitrate-N03 units? If so what is a safe level for our fish?

 

[Essjay]

Yes, API along with other brands use the nitrate-NO3 scale.

20 ppm nitrate-NO3 is now regarded as the upper limit for fish. Where tap water has higher than this fishkeepers use various methods to lower it, from using RO water and nitrate filters to prefilter tap water to growing terrestrial plants with their roots in the tank.

 

[Essjay]

Just a thought - the labs which tested your water, I wonder which scale they use? Did their reports say which?

 

[gwand]

Just a thought - the labs which tested your water, I wonder which scale they use? Did their reports say which?

EPA Primary MCL nitrate plus nitrite as N

 

[Essjay]

So the reason they were lower than your test kit is because they're using a different scale, got it

 

[TwoTankAmin]

A little science here will help.

There are two different scales used to measure the nitrogen compound relevant to us- ammonia (NH3), ammonium (NH4), nitrite (NO2) and nitrate (NO3).

The scales use by science is the Ntrogen scale. That only measure the N [art of thoe chemical fornmulas. As you can see they all have a single N atom. So 1 ppm of NH3 = 1 ppm of NH4 = 1 ppm of NO2 = 1ppm of NO3.

Most of our hobby kits measure using the Total Ion scale which counts all the atoms- i.e, the Hs and Os.

Like miles and kilometer or temp. in f and C can be converted to each other the same is true for the 2 scales.

The 10ppm of allowable nitrate is measured using the nitrogen scale. Using the total ipon scale makes it come to over 20 ppm. But mnitrate tests are a but inaccurate.

The most obvious place to see this is when the Dr. Hpvanec tells us during cycling not to let ammonia or nitrite to exceed 5 ppm. he is using the Nitrogens scale. On the Total Ion scale that would mean 6.4 ppm for ammonia and 16.4 for Nitrite. When it comes to nitrate 10 ppm as nitrogen becomes 44 ppm on the total ion scale.

NH3 = NH3-N * 1.21589

NH4 = NH4-N * 1.28786

NO2 = NO2-N * 3.28443

NO3 = NO3-N * 4.42664

Assumed atomic weights: H: 1.008, N: 14.007, O: 15.999

 

[gwand]

A little science here will help.

There are two different scales used to measure the nitrogen compound relevant to us- ammonia (NH3), ammonium (NH4), nitrite (NO2) and nitrate (NO3).

The scales use by science is the Ntrogen scale. That only measure the N [art of thoe chemical fornmulas. As you can see they all have a single N atom. So 1 ppm of NH3 = 1 ppm of NH4 = 1 ppm of NO2 = 1ppm of NO3.

Most of our hobby kits measure using the Total Ion scale which counts all the atoms- i.e, the Hs and Os.

Like miles and kilometer or temp. in f and C can be converted to each other the same is true for the 2 scales.

The 10ppm of allowable nitrate is measured using the nitrogen scale. Using the total ipon scale makes it come to over 20 ppm. But mnitrate tests are a but inaccurate.

The most obvious place to see this is when the Dr. Hpvanec tells us during cycling not to let ammonia or nitrite to exceed 5 ppm. he is using the Nitrogens scale. On the Total Ion scale that would mean 6.4 ppm for ammonia and 16.4 for Nitrite. When it comes to nitrate 10 ppm as nitrogen becomes 44 ppm on the total ion scale.

NH3 = NH3-N * 1.21589

NH4 = NH4-N * 1.28786

NO2 = NO2-N * 3.28443

NO3 = NO3-N * 4.42664

Assumed atomic weights: H: 1.008, N: 14.007, O: 15.999

So the API kit (liquid assay) is total ions method. Thanks. Very helpful.

 

[Essjay]

I didn't want to be too technical and confuse anyone

 

[TNG]

A little science here will help.

There are two different scales used to measure the nitrogen compound relevant to us- ammonia (NH3), ammonium (NH4), nitrite (NO2) and nitrate (NO3).

The scales use by science is the Ntrogen scale. That only measure the N [art of thoe chemical fornmulas. As you can see they all have a single N atom. So 1 ppm of NH3 = 1 ppm of NH4 = 1 ppm of NO2 = 1ppm of NO3.

Most of our hobby kits measure using the Total Ion scale which counts all the atoms- i.e, the Hs and Os.

Like miles and kilometer or temp. in f and C can be converted to each other the same is true for the 2 scales.

The 10ppm of allowable nitrate is measured using the nitrogen scale. Using the total ipon scale makes it come to over 20 ppm. But mnitrate tests are a but inaccurate.

The most obvious place to see this is when the Dr. Hpvanec tells us during cycling not to let ammonia or nitrite to exceed 5 ppm. he is using the Nitrogens scale. On the Total Ion scale that would mean 6.4 ppm for ammonia and 16.4 for Nitrite. When it comes to nitrate 10 ppm as nitrogen becomes 44 ppm on the total ion scale.

NH3 = NH3-N * 1.21589

NH4 = NH4-N * 1.28786

NO2 = NO2-N * 3.28443

NO3 = NO3-N * 4.42664

Assumed atomic weights: H: 1.008, N: 14.007, O: 15.999

That’s useful!
Makes me feel better now that all the chemistry lessons all those years ago weren’t a complete waste. And atomic weights have real life applications, not just some things to memorise to pass exams .