Hi ButterfliesLittleFarm,
Looking at your diary and I can point out a couple things:
PH usually is corrected after adding nutrients as the PH may vary after mixing them.
Also I see that you're not feeding any nitrogen for quite some time. That is probably the cause of the yellowing if you ask me.
There's an indication saying to use the tablets you're using with the Easy Pellets (aka Easy Boost Organic Nutrition). Probably that's why the N is missing.