Dumped the buckets and reset. Went straight maxigrow with some hydroguard. I figured the water is hard enough that I'd skip the CalMag to save some PPM since the plants were getting tip burn AND looking chlorotic. At the end of the week, I checked and the new growth looks better (I've said that before, I know). I gave them a foliar spray of dilute FoxFarm GrowBig to hopefully address lingering deficiencies while also taking it easy on the roots. The two smallest... I dunno man, they might just be goners. I've already got the nutrients mixed and the space where the buckets are would just be empty otherwise, so I'll let them ride it out until they're definitely dead, but I think the damage may have been done.
hang in there. For the most part, these are pretty forgiving plants. After all, it is a weed. I screw up my pH all the time, so I feel ya.
Peace and may your GSC develop some StinkyBudz!