Hot weather, not enough super soil, Leaves Yellowing???????? Need Help. Am I losing these beauties?????

Hey pal. Your plants are just hungry. Supersoil is great. But you are growing autos, which can be very demanding on P-K. And your soil at this point is just slightly lacking that extra kick your autos need. If they were photos at this stage they'd be fine. But as I said, autos are much more demanding. You can add some powder adative. Or some worm castings to introduce some extra nutrients your autos are lacking at this stage in coming to the end of their life they are seeking that extra kick and are just showing that. So worm castings or high grade soil and a few cm on top or some powder ad and pour water on top and it'll give your plants that extra kick they need. As for microbial life, I do not see any negative affects such as die off from rot or random rust spots running down the edge of your leafs, but if you do ever run into bad micro life then all you need to do is run some h202 through it for a week with syth nutrients. But as I said, you don't have microbial life, just hungry gals. Good luck.