Well I believe I found out why my leaves were yellowing so much. Turns out I was under watering. Once I started adding a quart of pHed water on the days in between the fert-days and the mini-flush-days, leaf drop stopped and the yellowing slowed and the buds grew faster!

My guess is that I fixed my pH issue with you guys' help, which meant the plant was 'working faster' for lack of a better term. Since it had all the P it needed, it was able to grow faster and so consumed more water than I was used to giving it.

Even though she is almost half-yellow, the buds look way better than anything I've grown before! Many thanks!!