Quote Originally Posted by brent.roberts
don't get too uptight about getting really really accurate results.

I don't think anyone here will tell you they can advise you to run the pool chemistry much different at 40 ppm or 50 ppm You just need to know that you are near 40 ppm and not 80 or 10.
Give this man a cigar! People get a bit too paranoid at test results. Some need to be very accurate (FC, TC, CC) some are ok within a small range (pH),
some have a much wider range to be 'OK' in (TA, CH, CYA)