Thanks for dropping in Joe!
I seem to be able to read them best in low light or shade conditions.
I tried multiple lighting scenarios and feel comfortable that I read the results accurately, certainly with in 1 ppm.
It doesn't seem like you have many sources of DO besides aeration? I am assuming you don't have much of a phytoplankton bloom?
DO comes from aeration and light wind action and any blooms that happen. The past two summers have produced some serious blooms (a couple kinda scary looking), but this year has yet to produce any real obvious ones. My water has had a secchi reading of 18" all season and I just raised my 3 diffusers (3 feet off the bottom) in hopes that getting them further from the bottom reduces any updraft of clay/sediments.
Have you begun to keep a log? See any trends? Correlations?
This thread is my log, so I have not being doing the testing long enough to see any trends, I just got my kits.