Week 6 (2/14-2/20)
Day 36 (2/14)
Gave them all nutrients today. Still trying to get a handle on the nitrogen deficiency without going overboard. The last time I gave nutes it was Flower Week 1 at half strength. The yellowing slowed but overall the plants were lime green. This round I bumped them up to Flower Week 2 at 1/2 strength, giving them an increase in the base nutes.
Day 38 (2/16)
They seem to be getting back on track, slowly but surely. The white widow's outer branches are hella tall. I really want to bend them down but idk if it's too late to attempt as I worry about breaking them.
Day 40 (2/18)
Gave them water this morning. I went easy on it, only split about a gallon between them. I want them to get some moisture but dry out quickly so I can give them nutes again. The yellowing seems to have stopped, or at least really slowed. I raised up the light over the white widow, at the tops of her tallest branches were getting droopy and I think it was from being too close.
Day 41 (2/19)
So when I got home last night, they were looking pretty pathetic. Roc's auto seemed to yellow more, and the others seemed lighter green. Even though I had just watered that morning, I rolled the dice and gave them nutes. I bumped them up to Flower Week 4 on the schedule, at half strength. That way they got a big nitrogen boost, and started the Bud XL. This morning they seemed more perky and hopefully happier.
Might I suggest a fulvic/humic/seaweed supplement just a ml or two per gallon. It should help keep things soluble. And definitely check your ph pens calibration.
Good luck!