Accuracy Of The Api Test Kit

[Fishmanic]

I bought the API test kit when I first starting to do a fishless cycle in my 35 gallon hex tank.   After about at least 60  tests of the ammonia level ,  I noticed there is about  3/4 bottle of solution left in bottle #1 and maybe 1/4 lof a  bottle of solution left in bottle 2.   I also noticed when I did a single drop test on a table surface,  bottle one had a thinner consistency than the solution in bottle #2.    Is this normal for bottle #1 to last longer than bottle #2?   
 
Also,  do you find the test kit to be accurate?  Have you compared this test kit to another brand side by side to check accuracy?  I want to be sure I'm getting a accurate readings during my cycle.

 

[ADW1988]

It depends where you get it from. I havent (touch wood) had a problem but have deinitely heard from friends that their Nitrite bottle showed 0 ppm and LFS (also using API maste) showed +5ppm
 
Same sort of thing I guess...
 
There is a difference in consistency between the Ammonia bottles (and the NitrAte bottles) that is normal.

Some not from recognised shops/sources may have been sitting in differing temperatures, or even past sell by date or any other variable? Mine was bought this year and Exp in 2018..

 

[the_lock_man]

Unless you have your samples tested by a lab with regularly calibrated test equipment, there is no way that you can know what is accurate and what is not. The API kit is renowned for being difficult to tell the difference between 0.25ppm and 0ppm on the ammonia test, under certain lighting conditions. It is also renowned for having an unreliable nitrate test, as there is a powder reagent in bottle no.2, which can precipitate out of solution. If the powder is not fully dissolved, it will not record the full proportion of nitrate in the sample.
 
The thing with having one bottle running out quicker than another is another little manufacturer's ploy to get more money out of you - you pay for what goes in the bottles, not what comes out. They won't sell you just one bottle. For ammonia, I use the Salifert test, which is a one-bottle test, so I won't have that problem.

 

[Shaddex]

Bottle #1 of ammonia test solution always runs out first for me.
I think its because its more viscous that #2 so each drop is actually more
 
Re Test results, Im pretty happy with the results I get.  Not compared them to a different brand but they seem to be accurate enough for my tanks.

 

[KirkyArcher]

The API test kit is accurate enough as in fit for purpose (if you follow the instructions to the letter)

 

[the_lock_man]

Certainly, they are accurate enough for our purposes. I guess the point I'm trying to make is regarding the question about running the same test with 2 different test kits. There is no way of knowing which one is the more accurate.

 

[silenthawk2x3]

The API is chemically the most accurate, because most others are paper strips with the chemical indicators trapped in the paper... Technically as long as you follow instructions the API will be the most accurate. We use a pill in my Environmental Science course, but it is not nearly as accurate or consistent as the API. We have a pill form indicator for phosphorus, dissolved oxygen, nitrate, and ammonia. The readings are inconsistent at best, but we use them... Any liquid test kits are generally more accurate. And to ensure accuracy usually you can do the same test repeatedly and really whichever is most consistent is generally more accurate. (Within reason) Consensus over several kits really show which are the best. To put it this way... If we were doing water testing in my Organic Chemistry course, which we're not (sadly), we're distilling EVERYTHING, we would use the same chemicals in the API test kit, but have to conjure them ourselves.