Okay, the threat has passed, and we can all breath a collective sigh of relief!
I am please to announce that, after some digging through my notes from the previous maintenance that necessitated the coolant & water replacement, it turns out that the G-05 + water mix I used was indeed mixed with distilled water. Woo-Hoo!!
Once I read my notes and realized the coolant/water I added was already mixed, it dawned on me that the purified drinking water I bought never got used (for the car's coolant anyway). I had mixed what was left of some 100% G-05 with what was left of the distilled water after the coolant replacement I did last year, and it's been sitting on the shelf ever since. Not remembering the water was already in it, I grabbed some that day (the purified drinking water) to mix with it before draining old coolant and working on car that night. But then I re-remembered the water was already in the coolant and that I didn't need to add any more water. Which meant the purified stuff was set aside for something else (IIRC I used it while washing the car later a few days later).
Confusing? I would imagine, and I am sorry for that..
Convoluted? Sure, but that's just how my life usually plays out...
The absolute truth? Yep, and I've got documentation to back me up...
Possible early onset Alzheimer's?
I certainly hope not, but my misspent youth and decadent middle ages surely did some damage to the ole noodle, so anything's possible...which is why you should always make notes when you work on your car! This is a perfect example!!
Now the only question becomes what do I do with the extra money and time I find myself with since I will not be buying any expensive engine coolant and rolling around under my car doing a D&F...I know, I'll hit the store and get me some Nolan Ryan top sirloins and a couple of beers and do some grilling and drinking (followed by eating!) with that time and money.
Thanks again to everyone for the quick responses,