It really does not matter if you add the reagent first or the pool water first. Probably easier to add the reagent last since it is in a dispenser bottle and easier to control the amount you put in. The important thing to do is shake the bottle for about thirty seconds to mix the two, let it sit for a minute or two, shake again to disperse the precipitate, and then slowly add to the CYA test tube until the black dot just disappears. Hold the tube around waist level and be in a shaded area for the most accurate reading for this test. And yes, it is the little plastic bottle with the squirt top! The only way to really screw up this test is to not give it time for the cloudiness to develop.
Btw, if no chemicals have been added to the pool you SHOULD get a reading showing no CYA!
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