Most Accurate Water Testers

[nzafi]

I was wondering what the most accurate testers are to test ammonia, nitrite and nitrate are. I have been using the ones by API where you use a test tub of water. The tester keeps showing up that I have ammonia in the tank (about .25) but I don't understand this because I am running a FX5 on a 75 gallon. The tank has been running for about 12 weeks, is cycled and there are about 12 tiny fish in there. The fish load is so small that there should be no ammonia.

Also, when I test nitrates I always have to test twice. The first I test, nitrates always show up at 0 and then when I test a second time they show up either orange or red. No idea why this keeps happening.

I am also struggling with telling the colors apart.

Sure others must experience this. Are there proper electronic testers or more robust testers out there?

Thanks!

 

[administrator]

Electronic testers are the most accurate but are expensive to buy and maintain. They require regular maintenance like calibration and replacement of probes. You have to buy special solutions to calibrate the units properly. If you have the time and money, go for it. If not, the liquid tests are as good as it gets. I am not a fan of the test strips.

 

[pacu mom]

I was wondering what the most accurate testers are to test ammonia, nitrite and nitrate are. I have been using the ones by API where you use a test tub of water. The tester keeps showing up that I have ammonia in the tank (about .25) but I don't understand this because I am running a FX5 on a 75 gallon. The tank has been running for about 12 weeks, is cycled and there are about 12 tiny fish in there. The fish load is so small that there should be no ammonia.

Also, when I test nitrates I always have to test twice. The first I test, nitrates always show up at 0 and then when I test a second time they show up either orange or red. No idea why this keeps happening.

I am also struggling with telling the colors apart.

Sure others must experience this. Are there proper electronic testers or more robust testers out there?

Thanks!

Old thread, but I'm responding anyway. I also was having tremendous difficulty reading API test results. I don't see much difference between the 10 ppm and the 20 ppm colors. I just got one of these yesterday. I like it a lot. My nitrates are lower than my guestimate on the API color chart.
https://hannainst.com/nitrate-portable-photometer-hi96786.html

 

[duanes]

As a former chemist/microbiologist, it seems to me the most common problem in aquarium water testing, is that the tubes are not rinsed of residual (not using aseptic technique).
When I did any testing for nitrate, ammonia, or even pH, tubes were rinsed a minimum 3 times with DI water before, and 3 times after each individual test. Because DI water is free of all chemicals, it will quickly remove any residue that can skew the tests.
Because we are dealing with ppm (minuscule amounts) even a pin head size drop from a previous test can skew the test results of another test.
I also believe using tap water to rinse can be problematic, especially if the tap water contains chloramine. The chloramine in a rinse can show up as trace ammonia and even nitrate in some colorimetric tests.

 

[nzafi]

Old thread, but I'm responding anyway. I also was having tremendous difficulty reading API test results. I don't see much difference between the 10 ppm and the 20 ppm colors. I just got one of these yesterday. I like it a lot. My nitrates are lower than my guestimate on the API color chart.
https://hannainst.com/nitrate-portable-photometer-hi96786.html

I thought these automatic testers required expense re-calibration often?

 

[pacu mom]

As a former chemist/microbiologist, it seems to me the most common problem in aquarium water testing, is that the tubes are not rinsed of residual (not using aseptic technique).
When I did any testing for nitrate, ammonia, or even pH, tubes were rinsed a minimum 3 times with DI water before, and 3 times after each individual test. Because DI water is free of all chemicals, it will quickly remove any residue that can skew the tests.
Because we are dealing with ppm (minuscule amounts) even a pin head size drop from a previous test can skew the test results of another test.
I also believe using tap water to rinse can be problematic, especially if the tap water contains chloramine. The chloramine in a rinse can show up as trace ammonia and even nitrate in some colorimetric tests.

I ordered the special cleaner, but it is back ordered. Even if there was chloramine, I would get a higher nitrate reading, and I am OK with that (especially since the readings are lower than my guessing on an unclear color chart).

I thought these automatic testers required expense re-calibration often?

Not expensive--the two cuvettes for recalibration are provided. Just plop in and push a button.


My problem is that I have great difficulty reading the color chart.

My reading was 7.6 on the Hanna.

 

[duanes]

When I did tests in the lab, to get accurate results we used a computerized spectrophotometer to analyze the differences in color, because the human eye, is subject to many conflicting influences, variation, and intensity of light, natural or artificial light (including bulb type) and even the endless degrees of partial color blindness.
Some of us don't realize how color limited we are.
The problem with spectrometers is cost (the one I used cost more than my truck), technical complexity and frequency of maintenance, and that many still need the same, and fresh reagents as bench tests.
Some reagents had to be "made" weekly because shelf life deteriorated so fast.
And to ensure accuracy, a known standard, a DI blank had to be run with each test.
Below for ammonia there is a 2ppm standard, a DI blank, and my tank water, all 3 (or more) were run with each bank of tests to assure accuracy

In the lab where I worked, we tested the finished water for ammonia and nitrate twice per shift, because our disinfectant was chloramine, so I always added an aliquot of tank water to the bank of ammonia and nitrate tests.

 

[pacu mom]

I haven't read the instructions on recalibrating the machine if it needs recalibrating. Figured I'd cross that bridge when I got to it. I have to make sure the cuvettes are clean--no finger prints, etc., for an accurate reading. Reagents come prepackaged and are opened and dumped in the test cuvette after initial "zeroing" the cuvette. Cuvette with reagent is shaken for one full minute before placing in the machine for reading. Prior to running my sample, I run the blank and then the standard cuvette in the machine to make sure calibration is within limits. It's a pretty painless process, and I am not going crossed eyed trying to guess what my nitrate level is. I'm happy that my nitrate levels are lower than I thought.