Lose of Green

plants look lighter green under grow lights, fyi... So, look at them under normal lighting or dim your lights signficantly.. i bet they are lusher than you believe them to be. first pick does look like a possible nitrogen deficiency. more hours is not necessarily better. Read up on Daily Light Integral. The wiki will explain it clearly. You can guesstimate DLI from light specs which may help decide if the extra hours is necessary or not -- in the end you still primarily use the plant's own growth to determine light intensity -- internode length is the key.

Check the light ppfd and the environment vpd. Looks like light burn to me, too high a PPFD range. Good luck, hope it gets solved soon. Your other notes looked fine to me.