You could add something that will rot into a jar and find out what your ammonia test kit will say. But that serves a merely theoretical purpose if the test kit should turn out not to be sensible enough.
I got API and Dry-tab test kits and two different tanks that are in different rooms and I'm too lazy to swap test kits.
The API test kit I use with the brackish tank and it shows now always 0 on ammonia/nitirite/nitrate as the tank has some plants and is rather under-stocked.
In the past, during cycling, and subsequent mini-cycles, and occasional HEAVIEST overfeeding (I'm overfeeding all the time), the API test kits showed reasonable figures on all three substances, e.g. ammonia and nitrite 0.25 ppm or 0.50, nitrate 5, 10 or higher up to 80.
When I now had a cyanobacteria outbreak and measured in the marine tank with the Dry-tab test kit I got ammonia/nitrite/nitrate 0.25/0.25/40 ppm.
The API test kit with the same water showed ammonia/nitrite/nitrate all zero.
To get an idea what's going on, I tested my RO water and my tap water with the Dry-tab test and with those water samples the Dry-tab shows everything zero as expected.
So, it looks like that the API test is simply not sensible enough. What is most astonishing is that the API nitrate test colour chart has a colour for 0 and the next one for 5 ppm. It showed zero on the marine water.
But the Dry-tab test has colours in steps of 0, 20, 40, and showed 40 ppm for the same marine water but zero for both tap and RO water.
I did those tests twice on two different days with exactly the same results.
So, somewhat fishy is going on there. There is a difference between the nitrate in the tank water and RO water that the API test doesn't show even with the finer grained steps of 0 and 5 ppm.
I forgot to mention that I got also an oxygen test from Salifert that showed always zero with every water sample even with the LFS's water.
I got the test replaced and now I am getting reasonable results. That is 5 ppm in the marine tank and 8 ppm in the brackish tank.
) never change colour they remain the same. Ammonia test sample is a mint green colour and nitrite is clear and pretty much colourless with a hint of bluey green ( that is if you try really hard to see it). I have tried numerous different samples and they all give the same result. As you may have read in my last thread I have two clowns and my CUC in the tank which are thriving; doesn't sound like 0.5 ppm of ammonia and 0.1 ppm nitrite are in the tank does it? 
