Browing/dieing leaves

So, this has been happening to just about all my plants. It seems to start with the older leaves and has been working its way up. The leaves seem to brown and dry out and then they fall off. Its not bugs (i checked multiple times). I tried adjusting my soil PH With lime about a week ago and the problem has progressed at the same rate as before. Also, i tried not doing anything in one set of pots while putting more nutes (MGrow) in another set. That did not seem to help. At this point i have no idea what i should do. Could it be Heat stress or a Magnesium problem? The temperature dose go between around 80-85 in the day to low 60's at night.

Even healthy plants get some fan leaf drying towards the bottom of the plant, but yours looks pH or nute related. When you tested the pH what was it?

The PH Was acidic, based on the little color chart they gave me, it looked around a 6.0. With that said, i don't believe what is happening is normal for these plants as now alot of the top leaves around the bud are affected, the bud in the center of the photo is the type of damage i'm talking about

Ok then the next thing would be root binding that is setting in, I'd say. How big is your reservoir per plant? Have any more pics?

They are growing in soil in 1.5-2.5 gallon pots

You have nitrogen burn on the older leaves, the newer upper leaves look like they are growing better as the later watering diluted the fertilizers in the pot. Flush and slow down on the feeding and the problems should go away. The already damaged leaves will not recover.

Ok, i'm going to try to flush one of them and see what happens