Nice work on replacing something modern with something old!
Who cares if its a BOL model, as long as it gets the job done, you are perfectly alright! 6grains of water hardness is described as moderate hardness. I would definitely recommend you get some STPP from the link below, and add maybe 1/4-1/2 a tsp. with every load in the Main-Wash detergent cup.
If you have a recirculation system for your hot water heater, ensure that is running, that way, you don't have to race after the dishwasher when you here the ol' girl snap into the draining cycle. That, or just keep the water heater really hot, to help make up for any lack of heat as the line is initially purged.
Sorry to have to hijack this thread, but how many rinses do the KA's run post-wash, and how long do they run. This would determine whether Jen has to go and run the hot tap each time the machine drains, or just at the end of the Main-Wash. (I happen to do this for our DishDrawer, since we have solar heater water).
Also, does this BOL model run any Pre-Rinses/Washes?
If I were you, I'd have the water heater right up at 150F, that way, you'll get 100% detergent dissolving in the relatively short Main-Washing period (and it'll help sanitise your dishes, if you happen to be a germaphobe, like me!)
One last question, could you tell us how long it takes you to run the water hot in your kitchen when the lines have sat for around an hour? That way, we could figure out whether you really need to "waste-water" running the tap (I s'pose you could justify it by washing your hands lots, *lol*)
Congratulations and Good Luck with your KitchenAid. I envy you so much (Not because our DishDrawer is crap - its because I'd like to have a nice old dishwasher :] )!