A little more than a year to the day that I freed myself from the international seltzer cartel, I finally drained my CO2 tank, and swapped in a replacement.
I figure we’ve been averaging two to three liters of carbonated beverage a day (mostly water, though some juice, and a few other weird experiments), which is pretty much in line with the 1000-liter estimate I’d seen for a 20-lb tank. So my initial $240 investment worked out to a cost of about $0.24/liter over the first year.
From here on out though it really starts to pay off. The tank exchange cost only $18 with tax; that’s less than two cents a liter from here on out, compared to about a buck a bottle for two liters of the store brand variety. Sweet. (Well, actually, fizzy.)