Several home canners I watch on youtube suggest adding filler jars if you don't have a full batch to keep the movement to a minimum. I had the idea to fill the extra quart jar with tap water with plenty of chlorine already, added a lid and ring and canned it too. I've seen canned water you can buy for 3 to 4 dollars a can that has a 30 year shelf life. My clean tap water, boiled for 90 minutes... is there any reason it won't last 30 years? Also it's jars I have extra at this point I could always use the water or the jar again for something else if needed? Thoughts?