Does it matter if chemicals stick to the bottom of the dissolved oxygen (D.O.) sample bottle?
Yes and no. In general, having some chemicals clump on the bottom won’t cause a problem, since there are more chemicals in the pillow packs than are needed for a complete reaction. However, if a lot of clumping occurs it could be a problem and you might notice that the color of the solution is lighter than normal (the trick is remembering what color is normal!). So, here’s the solution: don’t delay capping and shaking the bottle vigorously once the D.O. #1 and D.O. #2 reagents are added, since it is really hard (if not impossible) to get chemicals off the bottom. If you have any doubts about the degree of clumping, continue, then repeat the test and compare results.
