Mash the blueberries a layer at a time in something like a pie plate using something like a potato masher.
Add to a large pot, along with the spices.
Add the calcium water to the pot.
Put on burner to start coming to a boil.
Meanwhile in a bowl whisk together the pectin powder and the lemon juice, adding the lemon juice all at once to the powder and stirring it quickly. Set aside.
When blueberries have come to a full boil, stir in the lemon juice mixture a dollop at a time.
Bring back to a boil, if necessary, and then let boil for another minute.
Remove from heat.
Stir in the stevia. Taste. Add a bit more if desired.
Ladle into 125 ml (4 oz) or quarter-litre (½ US pint / 8 oz) jars.
Leave 1 cm (¼ inch) headspace.
Debubble, adjust headspace.
Wipe jar rims.
Put lids on.
Process in a water bath or steam canner.
Process either size jars for 10 minutes; increase time as needed for your altitude.