I know it's different media and nutes but my first grow my plants did the very same thing. I game them nutrients, not too much water but still kept getting yellow and dying leaves. I'm not sure if this is true but the ladies will take nutrients from the leaves to help assist the the flower production. It will start to eat itself. If there isn't enough nutes. Some people welcome this so all the nutrients get used up and flushing at the end seems easier. Those guys were a bit advanced and knew what to look for.Been having some major issues for a little while now that i cant seem to get a handle on. I am in week 5 of flower and things just look like shit if u ask me. Leaves have been dieing off yellowing and all sorts as well as slow flower growth. Ph has been keeped between 5.8-6.3 and ec of 1.2 using maxibloom. Here are some pics