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.
Add the calcium water to the pot.
Put on burner to start coming to a boil.
Meanwhile, put the pectin powder in a bowl. Mix in the sugar, if using sugar. Then whisk in the lemon juice all at once (along with the liquid stevia, if using instead of sugar. If using honey, mix the lemon juice and honey first, then whisk into pectin powder.) 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.
Ladle into 125 ml (4 oz) or quarter-litre (1/2 US pint / 8 oz) jars.
Leave 1 cm (1/4 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.