nutrient problem

Hey guys, I wanted to seek some help as I am about to flip my third round of ladies into flower and seemed to get the same problem with the first two grows. First two rounds were Honey Cream (first from seed, second from clones), and this third round will be Honey Cream and Lemon Shining...

Long time lurker, first time poster, first time grower. I think I have a pH problem, but I'm not totally sure and I'm not sure how to fix it. I have four, 7 week old autoflowers going. They're growing in Coast of Maine Stonington Blend, in 5 gallon smart pots. They're under 400 watts of 3000k 90...

I'm starting week 2 of flower on these gg4 and noticed the lower leaves are starting to turn yellow/rust and die off. Any help is greatly appreciated. Thanks on advance!