I give them 5ml of cal per gallon of ph water and other organic nutes heat stress yes I've move my lights to the top of tent now when I was having these issues the temp did grow to 85 but that's all under control I also thought maybe some standing water was left on the leaf and the lights burned it off ..
Whatever it is, it's not much. Probably a little nutrient deficiency. Overall they look pretty good though. You'll have to provide a little more info about your process before we can make a serious guess about it though. What is that white stuff on top of your soil? Usually heat stress will cause them to wilt down a bit and I don't see that going on here. Is your pH tester reliable? I say this because the really cheap ones don't always read correctly and I found the drops very hard to use since the range is so precise that you need to reach. I had one that turned out to be off by 2 or 3 points every time so weird things were happening with my plants even though I thought I had it under control. Watering habits are a biggie too. Do you allow definite wet/dry cycles in your watering process?
Just found out my ph meter has been off calibrated it and now it's right but I've had wrong ph the whole time so they now have a salt build up so gotta do a flush can anybody tell me the best way to go about this should I use 3 times the water of the container with the right ph water Ph was 9 and up most likely
I usually water every 3 days or untill the pot feels light the smaller ones are in 3 gallons and the bigger ones are 7 but I stop watering every 3 days because a few of them look like I was over watering but now coming to realize it was a ph problem and this is why they all have different problems ..