I think my api ammonia test is lying to me.

[jcarson]

Hey MFK

After testing for ammonia today in my oldest tank (which I haven't done in months) it read 0.25 ppm this tank has been up and running and cycled for over 7 months now. So naturally I thought my regents were lying so I shook them bottles up some more and tested again and got the same reading so I tested my other tanks in the house and got that same 0.25 reading on all my tanks.

All 4 of my tanks have various stocking levels from heavy to light.
All 4 my tanks have the same ph and kh and temp.
All 4 tanks have the same nitrite reading of 0.
I keep all 4 of these tanks at nitrates from 5.0 to 10 ppm through frequent water changes

My water from the tap have tested 0 for ammonia and 0 nitrites.

So I used a different test for ammonia (some dip strips) and those readings are 0.

The api liquids are current and dont expire till the year 2022.

If I can't rely on my test kits..... then what?
Sorta confused.

 

[tlindsey]

Hey MFK

After testing for ammonia today in my oldest tank (which I haven't done in months) it read 0.25 ppm this tank has been up and running and cycled for over 7 months now. So naturally I thought my regents were lying so I shook them bottles up some more and tested again and got the same reading so I tested my other tanks in the house and got that same 0.25 reading on all my tanks.

All 4 of my tanks have various stocking levels from heavy to light.
All 4 my tanks have the same ph and kh and temp.
All 4 tanks have the same nitrite reading of 0.
I keep all 4 of these tanks at nitrates from 5.0 to 10 ppm through frequent water changes

My water from the tap have tested 0 for ammonia and 0 nitrites.

So I used a different test for ammonia (some dip strips) and those readings are 0.

The api liquids are current and dont expire till the year 2022.

If I can't rely on my test kits..... then what?
Sorta confused.

I learned this from a very knowledgeable member duanes that if you use the vials for the regent's without rinsing them with distilled water the vial's will eventually stain and the results will be a false reading due to coloration after testing. I'm sure your parameters are good. I've been rinsing my vials ever since with no issues lately.

 

[Jexnell]

Also if I remember right. If your city uses cloramine (not sure if this is the right word) instead of clorine it can come up with the slight reading you are getting.

 

[duanes]

Both the above responses are right.
Because I was a chemist/microbiologist for a water quality lab. We had strict rinsing rules, and when they were not followed, tests often showed flawed results.
Because when we test we use such a tiny amount of water (1mL) to extrapolate, to test miniscule amounts (ppm of a substance) any slight residual left in a tube can result in flawed numbers.
we were required to rinse each tube, with DI water, 3 times between each test. And when done testing for that part of the shift, turn tubes open end down, on a towel.
If we rinsed in tap water, ammonia and nitrate noise often was the result, because the chloramine in our tap water often appears in those two forms.
If I rinsed in just tank water for my own tests, any slight film could skew results, any residual semi-evaporated drop could also create abhorrent numbers.
And long term use of either as a rinse, or without DI rinsing can really skew the numbers.
Consider 1 ppm in 1 mL of water....molecular in scope.
I suggest you buy a gallon of DI water from the grocery store, soak your tubes in a little, for a day, then rinse a few times in the same DI water, and then test.
If the tests still create ammonia noise, then maybe the reagents went bad, but its usually operator error iwith sloppy rinsing and technique my experience.
And this is not to single you out, I often tested pro-operators who were in a hurry, and was amazed at their erroneous results, as compared to when proper Aseptic technique was used.

 

[duanes]

One other thing I'd like to mention, because some tests use capped tubes for shaking up the sample.
Those caps also need similar rinsing.

 

[jcarson]

I learned this from a very knowledgeable member duanes that if you use the vials for the regent's without rinsing them with distilled water the vial's will eventually stain and the results will be a false reading due to coloration after testing. I'm sure your parameters are good. I've been rinsing my vials ever since with no issues lately.

Both the above responses are right.
Because I was a chemist/microbiologist for a water quality lab. We had strict rinsing rules, and when they were not followed, tests often showed flawed results.
Because when we test we use such a tiny amount of water (1mL) to extrapolate, to test miniscule amounts (ppm of a substance) any slight residual left in a tube can result in flawed numbers.
we were required to rinse each tube, with DI water, 3 times between each test. And when done testing for that part of the shift, turn tubes open end down, on a towel.
If we rinsed in tap water, ammonia and nitrate noise often was the result, because the chloramine in our tap water often appears in those two forms.
If I rinsed in just tank water for my own tests, any slight film could skew results, any residual semi-evaporated drop could also create abhorrent numbers.
And long term use of either as a rinse, or without DI rinsing can really skew the numbers.
Consider 1 ppm in 1 mL of water....molecular in scope.
I suggest you buy a gallon of DI water from the grocery store, soak your tubes in a little, for a day, then rinse a few times in the same DI water, and then test.
If the tests still create ammonia noise, then maybe the reagents went bad, but its usually operator error iwith sloppy rinsing and technique my experience.
And this is not to single you out, I often tested pro-operators who were in a hurry, and was amazed at their erroneous results, as compared to when proper Aseptic technique was used.

So to see if this was the case (not that I didn't trust you) I wanted to see the readings after testing my tap, my bottled drinking water and my tank again to see what readings I would get and let's just say I am going to the store right now to pick up some distilled water.

Thanks for everybody.

 

[deeda]

DI (deionized) water is different than distilled water so see if your store has it.

 

[jcarson]

DI (deionized) water is different than distilled water so see if your store has it.

Dang, I thought they were the same.

 

[JK47]

If you leave out the sample overnight, the tube will turn yellow with no ammonia and super light green if there was ammonia. It isn’t accurate to any ppm or specific number since it isn’t made to sit overnight. It’s a nice little way to get a “finger in the wind” if you’re on the fence trying to read that lowest .25 reading on API.

 

[tlindsey]

If you leave out the sample overnight, the tube will turn yellow with no ammonia and super light green if there was ammonia. It isn’t accurate to any ppm or specific number since it isn’t made to sit overnight. It’s a nice little way to get a “finger in the wind” if you’re on the fence trying to read that lowest .25 reading on API.

I didn't know that thanks for the great tip.