False positive API test ammonia

[AlexT]

Anyone ever had this? I've had it twice now for my main set up. It has come back 0.50 Ammonia. I test each morning because it's still a new set up. I also test some evenings.

When I have had the false positives, when I do another test 10 minutes later it is back to Ammonia nil again. And then, I'll do it again 10 minutes later NIL, and again that evening NIL.

I'm either not rinsing the test tubes out well enough from the previous test, or I am not shaking the x2 ammonia test bottles enough in the morning.

So over the course of the last few weeks we are talking about at least 40 tests for ammonia and 20 or 25 for nitrite. Nitrite is always nil. So in about 40 tests, I've 38 coming back NIL and 2 coming back 0.50.

The test kit is only 5-6 weeks old and all my other API in the master kit are performing "normally" I think.

 

[Essjay]

What is the lighting in the room where you read the the latest tests?

Natural daylight, but not in direct sunlight is best.
Fluorescent lights can make the liquid look greener than it really is.
Old incandescent lights did not affect the colour.
I really must test what our LED lights do to the colour.......


If it's the same in London as it is here it's started going dark very early the last few days (too much thick cloud), which is why I ask about the light.

 

[AlexT]

What is the lighting in the room where you read the the latest tests?

Natural daylight, but not in direct sunlight is best.
Fluorescent lights can make the liquid look greener than it really is.
Old incandescent lights did not affect the colour.
I really must test what our LED lights do to the colour.......


If it's the same in London as it is here it's started going dark very early the last few days (too much thick cloud), which is why I ask about the light.

Definitely worth considering. However, these 2 false positive's have been flat out green on the API colour chart, perhaps merging between 0.50 and 1.00 ppm. Most of the time I do ammonia and nitrite readings, I am doing two different tanks at the same time. My main tank, and my quarantine tank. This comes in handy because then you can have two vials next to each other you can compare the colours, plus of course, the colour chart. Also, when I had my x2 false positive ammonia tests, I also checked the tap water which come back as NIL (i.e. definitely yellow on the API chart) and I do all the readings under the same daylight.

But your points are important, so thanks for sharing.

 

[UnityLover]

Anyone ever had this? I've had it twice now for my main set up. It has come back 0.50 Ammonia. I test each morning because it's still a new set up. I also test some evenings.

When I have had the false positives, when I do another test 10 minutes later it is back to Ammonia nil again. And then, I'll do it again 10 minutes later NIL, and again that evening NIL.

I'm either not rinsing the test tubes out well enough from the previous test, or I am not shaking the x2 ammonia test bottles enough in the morning.

So over the course of the last few weeks we are talking about at least 40 tests for ammonia and 20 or 25 for nitrite. Nitrite is always nil. So in about 40 tests, I've 38 coming back NIL and 2 coming back 0.50.

The test kit is only 5-6 weeks old and all my other API in the master kit are performing "normally" I think.

Api also detects bound ammonia, which is harmless.

 

[Essjay]

Our test kits test for all forms of ammonia, be they ammonia, or ammonium or bound to whatever those ammonia detoxifying dechlorinators do. And whatever those ammonia detoxifiers do, it wears off after 24 hours.
The ammonia form is the one to worry about as that's the toxic one. Ammonium is a lot less toxic, but long term it still harms fish. The amount in each form varies with pH and temperature.
In part 2 of his fish-in cycling guide, TwoTankAmin tells us that ammonia can be up to 0.05ppm for a few hours and up to 0.02 for a few days. Well below 0.02 ppm is OK. Those are actual ammonia levels not the readings with our test kits. We have to calculate how much of our ammonia reading is actual ammonia.

Free Ammonia Calculator

Aquarium calculator; Estimate the free (un-ionized) ammonia (NH3) concentration, given the total ammonia concentration.

www.hamzasreef.com

Set salinity to zero, enter the ammonia tester reading, the water temperature and the pH in the boxes and hit 'calculate' Look at the number in the 'NH3 concentration' box.