Thanks for the reply. Yes I do use water conditioner when doing water changes and also when I setup this tank. I use Seachem Prime, if I detect any further metals in the water after that I always have Dechlor brand conditioner. It's literally just a dechlorinator with nothing else added.I don't remember you saying you use a water conditioner, do you? And just for the record I don't believe your pH is negatively affecting your fish. ~8.0 is just about right for a JD. They're extremely hardy as well and I'm going to guess yours is captive bred, all these factors make pH less of a deterring factor.
As for the pH that's really helpful information, I like hearing that my H2O conditions aren't as bad as I thought. Maybe now I can stop worrying so much about getting that lowered. But this head 'thrashing' and 'shuttering' is definitely not normal JD behavior right? As of right now, my plan is to continue with the treatment schedule that I posted earlier, I'll be going ahead with the second treatment of Prazi Pro this afternoon.