Dude this problem didn't happen quickly you've been posting about these brown spots forming for at least 2-2 weeks now. I told you 2 weeks ago your plants were hungry and needed to be fed but you were afraid to do that.
You are making all sorts of uneducated guesses about what is wrong with your plants. Deficiencies don't always hit the lower growth first. Zinc deficiencies I believe are known to start at the top.
Your assuming a nutrient problem won't happen that fast, instead of realizing how slowly its been happening. Your assuming that feeding them locked them out instead of accepting that they are starving and eating themselves slowly. They likely have a few things doing on here.
PH could totally be an issue. I stopped using electronic PH testers a long time ago, I use the little drops and they work fine. You can get them at aquarium stores or grow shops. My nutes drop my PH to, so before I add my nutes to my water I add some PH up to balance that. Then once my nutrients are mixed they stay pretty stable since I set the ph to begin with. Adding the ph up before you add the nutes is important so you don't precipitate the nutrients.
I believe they are starving for Calcium, and potassium. Your leaves match those deficiency symptoms pretty well. The feed you gave them very well might help slow the decline but you can't repair it. Your plants are in the heart of flowering, they are needing more food to succeed. If you starve them they will die.
It didnt happen out of no where huh?
That's why 90% of the leafs that didnt have brown spots because brownish/dried out overnight, and the ones with the brown spots were the least affected?
That sounds pretty out of no where to me.
And I fed them twice since you commented on my last thing, AND top dressed them with about 3 inches of fresh soil, and things rapidly escalated over night? But still must be underfed?
If that was the case they would have shown improvement by now, or at the very least any damage would have slowed down.
Yeah they're probably starving for nutrients, but not because there is a lack of them, they're locked out.
And unedaucated guesses huh?
That's why I literally stated every reason for my assumptions in a previous post.
Dont come on here tell me I'm wrong and your right.
I dont understand why some people on this forum get so damn butthurt and upset when someone doesnt automatically agree with them, or when their answers might be incorrect.
And in no way am I saying your wrong, but based on everything (the information I am processing visually in person), nutrients being locked out is far more likely than lack of nutrients in the soil especially considering things rapidly going down hill post feeding.