so i checked the calibration and they say it's pre set and if out it would be 1-3% unless i want to spend money on the advanced which i don't so i will keep it at max at 16'' which measures around 1000 ppfd and watch what the leaf's do and see how much upward growth in the next few week's, i'm guessing i'm just reading to much stuff and over thinking & expecting quicker result's for what can't be rushed, i'm going deer hunting for 5 day's next week so when i get back i'm sure thing's will look different, thank's again