Corpse I've seen your posts detailing the issues you've been having with your girls, and aside from the heat getting to water in the buckets, I think another problem you have is growing plants way too big for those puny 5gal buckets.
If they were recirculated between each other with a large control res to up your water volume by at least double or triple, I think you'd be doing a lot better. If you really wanna stick with single buckets non recirculated then you're gonna need some 10-20 gallon containers.
When your plants are so big they drink nearly all the water available to them in a day, weird things happen as the res becomes depleted. Plants might take all the water but not all of the nutes, leaving a very high PPM mixture to burn your plant. PH will also fluctuate like crazy with big plants and such a small res.
It's like trying to keep 20 gold fish in a tiny little bowl, that water is gonna turn disgusting fast, and your fish are gonna die. You need more water volume to support them, either with a bigger container, or adding more water volume by means of a remote res and recirculating it.