I own two API test kits. The chemicals seem to work the same as far as coloring the samples, but the the damned color charts are not even CLOSE to matching each other! Which one to believe? We're talking as much as 2ppm discrepancy in ammonia and nitrites according to the charts for a given color in the test tubes. This could be critical for some people! Why don't they hire some decent printers capable of actually matching colors on production runs?

Likewise with thermometers. I now own 7 of 'em. Two are "lab quality" and they are within 0.25 degrees C of each other which is, I suppose, acceptable. I own 3 pool thermometers. Placed in the same water, they show a 12 degree F temp range! WTF? I just bought two digital thermometers of identical make, model, manufacturer. They don't even agree with each other (one degree F off). They also register 2 to 3 degrees F higher than the average of the two lab thermometers.

Production quality control is evidently a thing of the past. Very frustrating for the consumer when you're trying to be diligent on such things as monitoring water quality!

Sorry for the rant. Just had to get that off my chest.