Hey all just a quick question in regards to the master test kit test tubes! I find when I do the ammonia and nitrate test, and shake the test tube, I lose a lot of the liquid and fear its causing fals positives or inaccurate results. The caps are a little lose so I cover with paper towel to shake, or else I'd have test liquid flying all over the place and getting on me. When I do this though, I lose at least a quarter of the liquid. Any idea how I can avoid this or am I looking at replacing the test tubes?