I just tested my water when I got home from work which I do almost everyday. I was wondering if it is better to test in the morning before the sun has hit or in the evening so you know how much bleach to add. Testing in the morning could give you more consistent numbers for the past 12 hours with no effect from the Sun but testing in the evening gives you a better idea of how much bleach you need to add to get your numbers right. I may be overthinking it as my numbers are in a pretty good rhythm but I was just curious.