Water Quality Parameters

• When adding drops of test solutions to test tubes, hold the dropper bottles upside down in a completely vertical position to assure that the drops are all the same size.

• To invert a test tube: Make sure the cap is securely on the tube. Hold the top and bottom of the test tube between your thumb and pointer finger. Turn the tube completely upside down and then right side up again. Do this 4-5 times or until the solution is adequately mixed.

• When you are doing the Nitrate test, make sure you vigorously shake Nitrate Test Solution #2 for at least 30 seconds before you use it. After you add the drops of this solution to your test tube, you must cap it and shake it vigorously for 1 minute. Because Nitrate Test Solution #2 is an oil, these steps are extremely important to insure accuracy of your test results. 

• When you are determining test results, use the Color Comparison Chart on the back of the instruction booklet (NOT the one on the Water Testing Direction Sheet that I printed for you). 

• When you have finished a test and are comparing the color of the solution in your test tube to the Color Comparison Chart, the tube should be viewed in a well-lit area against the white area of the chart. The closest color match indicates your test result.

• When cleaning up after testing, rinse the test tubes and caps thoroughly with distilled water. Place tubes in a test tube rack to dry.

(Ref. 2)

• Many FREE, 3D-printable test tube rack designs for the API Freshwater Master Test Kit can be found online. You may download STL files for printing the design above here: https://www.thingiverse.com/thing:5342471