Mash the strawberries a layer at a time in something like a pie plate using something like a potato masher.
You should end up with around 1 litre (4 cups / 32 oz) of mashed strawberries. A tidge under or over is fine.
Put in a large stainless steel pot.
If using sugar or Splenda. put them in a bowl, add the pectin powder, and mix. If using a liquid sweetener such as honey or liquid stevia, ladle out about 4 tablespoons of juice and put in a small bowl. Add the pectin powder all at once, and stir it into juice. Set aside.
Add the calcium water to the pot.
Bring the pot to a boil over high heat.
Add the pectin mixture a little at a time, stirring constantly.
Let boil vigorously for another 2 minutes, stirring constantly.
Remove from heat.
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 jars for 10 minutes; increase time as needed for your altitude.