[mannyaf7]

Hello all, I’m a little confused about the readings for ammonia that I have in two different kits.
One is the API master test kit which comes with a test for total ammonia (the sum of NH3 and NH4+ levels) which constantly reads at 0.25ppm for me.
The other is a Hanna HI700 that supposedly measures something called “amoniacal nitrogen” (from what I could glean from articles this is also a total measure of NH3 and NH4+, correct me if I’m wrong). This one constantly reads above 3.00ppm for me though.
I understand the charts that detail ammonia toxicity as pH and temperature change, that is not the problem. The problem is, why are both giving me different readings? Have I misunderstood either terms, and they’re just measuring different forms of ammonia that I don’t understand?
Some help would be appreciated, as I have just changed the substrate in my nano tank, and would like to know if it’s safe to add fish.

 

[Darkblade48]

With multiple forms of measurement, comes increasing ambiguous conclusions, as you have realized.

I would err on the side of caution and assume that the ammonia is high (may be a false positive) - this is better than accidentally thinking your ammonia is negligible, and falsely assuming the water is safe for livestock.

Have you calibrated either of the test kits? There are ways to create reference solutions (for nitrates, ammonia, etc) and then calibrate your test kits/probe against them to ensure they are measuring correctly.

 

[mannyaf7]

You know what? I bought a third test (Seachem Ammonia Alert) and it verified that the API test kit was right. Then I looked up some charts detailing ammonia (NH3) vs Ammonium (NH4+) levels for my tank temperature and pH and came to the conclusion that my tank was safe.
Livestock has been in there 2 days now and there seems to be no problem.
I noticed that the Hanna sample was going “cloudy” when I added the reagents to test for ammonia. The directions on the package said that the sample should only develop a “yellow tint.”
So I did one more test: API vs Hanna for my tap water. Both tests came out accurate and no cloudiness on the Hanna. So I think to myself: What is in my freshly changed aquarium water that is not in my tap water? The solution: tap water conditioner.
I added a single drop of my Seachem Prime to the water sample I used for the Hanna test and lo and behold: the cloudiness that was making the test a false positive.
According to Seachem’s website, Prime contains a “binder” that detoxifies ammonia, nitrite, and nitrate. Maybe this is interfering with my Hanna test kit’s results. Goes to show how little we know about the chemical interactions goin on in our aquariums.