(New to growing)(Autos) Week 4 of grow/3 of feed, Are these readings okay?

[YBGTA]

Hello, hopefully I posting in right area, I had 6 autos, 1 of which died on my error but I have 5 now, my only concern is one has one brown spot on each of its first 2 leaves and I believe it's possibly from slashing if nute water as nothing else seems crazy wrong, the smaller one is my thai and I believe it's nute burn? The root growth is barely peeking from netpot. As for the deformation in leaves I believe it was a humidity issue but since can regulate around 70s-80 on room temp and around 68-74 RH,I have been trying to pay attention to my vpd ever since being able to control it a little better,ventilation is out of the question, one way in and out sadly, but I have a ac in the room and a fan blowing, let me know if my ppm and ec etc look fine to each plant, I plan to change their res sometime later today.

 

[ACSippi]

Since you're a new grower keep your PH at 6 throughout the plants whole life. When you get comfortable with everything you can tweak the PH.

Imho throw the yellow one away (ph tester), get and learn how to use drip tests, they're bulletproof. Check out my videos on YouTube OR my 'starting seeds' thread. Lots of good info targeting new growers.