If you need to verify that your test kits are reading properly, then verify your results with another test kit or use an outside laboratory. Using a friend’s test kit, or buying another brand of kit can easily verify whether or not your current test kit is accurate. But if you doubt your testing methods altogether, an outside lab can perform the test on a water sample for relatively cheaply. Just mail in a sample and not only will you get the result you are looking for, but you will also get many more water parameters that could help paint a bigger picture. Of course, sending water off weekly may be cost prohibitive, and some results are better shown in realtime, such as pH and ORP.