What is going on with my girls

I noticed it a couple days ago I took off a bunch of leaves off I checked today and they are looking like this not all over and it’s not every plant. It has been warm the past couple days and my res is in my room so my water got warmer could that be the problem? Any and all advice is appreciated I’m at the end of week 5 plz help

I use Mills nutrients no extra additives with tap water that has been in a 35gal garbage can bubbling for at least 24hrs and ph between 5.8-6.2 I try to keep it even 6.0 I’m also using bush doctor coco loco