Works as described!
There are basically TWO tests (2 vials) per packet. Due to being pricey,you don't necessarily<br />NEED to use them both unless the first test that you use is inconclusive. If the test sample<br />that you're using is legit,then you'll have an almost immediate 'color' reaction that matches the<br />corresponding color on the color chart. Therefore you can save the other test for a later application.<br />As long as it's within the expiration period.<br />  Note: this only detects the presence of,not the amount.
Rating: 4 stars