OK, got a camera and will answer the following ... will include pix of leaves with bright yellow spots and healthy leaves...any additional advice much appreciated!

H=hydro
R=RockWool
D=NFT
E- tap water
E-between 5.8 and 6.1
HRT-1.7 EC
E-6 weeks
E-Canna Nutes Flora
E-250 HPS lights
E-day temps btw. 78 and 92 (temps fluctuate because of attic heat), night temps btw. 68-78
HD-Reservoir temperature btw. 70-75
E-Lighting schedule - 12 hours on, 12 hours off (2nd week in flower)
E-Type of ventilation - intake and outtake fan plus desk fan at base of plant