Those little plants are cute. The dwc looks great. They look great to me, I think they should make it.
Good luck.
The pH climbed back up today, back into the 6's. From what I understand, there are many causes for this. I lowered the pH back down into the 5's.
I don't remember the reasons, but pH slowly climbing is a good thing. When you get your nutrients to a higher strength they will buffer it more so it doesn't change as much.
Also I don't know if you've already read this, but apparently the easy way to tell if you are giving the right amount of nutes in a dwc is to watch the ppm. If as the water goes down the ppm climbs then the plants are taking more water than nutrients, and you have too many (it may not be bad, just a waste of nutrients). If the ppm sinks they are taking more nutes than water and they need more. If the ppm stays the about the same then things are good. It's like goldy locks.
The cheap meters suck, waste of money. YOu can do the grow with out one. Just take good notes of what you add and keep a look out for deficiences and nute burn.
What time shcedule are you lights on. I read that they focus energy on roots in the night time, so if you are running 24/0 the roots might not be getting as good a chance to catch up as with 22/2 or something.
Things are looking good. You take good care of those little girls.
Hey bro... I do not know what the yellowing is. It doesn't look too bad to me, although I'm sure it's very disconcerting.
It definitely doesn't have to do with temps (in my newb opinion).
It may be a deficiency, but it is only on those bottom leaves... I don't know much about them, but I feel like they show on more than just the bottom leaves. My guess is just that the plant is taking energy from the bottom.
Don't stress, give it a day and if things are worse you can worry a little more. I think it will be ok (let's hope I'm right).
Mary Jane is a little shrub huh. Dude your plants are taking off. I guess they got over the transplant.
Things are rolling now.
Good work with everything.