first, thanks for the helpful suggestions.
I immediately raised the light to 12"
I'll need some time to filter some more RO water to address #2 - using this schedule...
My meter only measures ppm, I will check out using an EC meter
The 6.0 - 6.1 pH is my target, assuming accurate metering...
First post here and first attempt at growing
RDWC - 32 gal total in two totes - one plant - 700 gph pump (yes, massively overbuilt ;-)
Chiller - water temp stays between 60 - 68 degrees F
600 watt MH that is about 4 inches from plant
temp at top of plant ranges between 70 - 80 degrees F...