Whether overfed or underfed depends on how frequent you feed, amount of nutrients fed and the medium they are in. Some mediums need a lot of supplemental food, others not so much. Depends on your schedule but going without any nutrients for two weeks in the middle of flower is a bad idea...
How long has there been leaf discoloration? If its going from the bottom up until they fall off, likely screaming for nutrients. I dunno if I would have started giving straight water two weeks ago if there are 3 weeks left. Usually that is something you do right before harvest if you want to at...
Adjusting ph isnt only for hydro, its just much more sensitive than soil would be. Yes soil is a natural buffer but you would still need to ph if your water is at 8, especially when feeding anything. My water is 8.5 out of the tap and have issues if I dont adjust.
I have run seedsman blueberry a few times, there is one pheno that is really good, couple others not so much. No hermies though, only dp blueberry has hermied on me.
Hopefully turns out well for you man
I've always thought about getting some Durban poison going but the flowering times and stretch have been a deterrent. I'm sure it would turn out okay, just need patience which I'm not the best with.