TIL! Not the first time I've made a mistake on account of failing to detect that a different English was being used.
replyI assume it's a local/informal unit of measure? DDG doesn't know what a "plastic gallon" unit is.
replyIt's not really a unit of measurement but rather just what you'd call the container[1], which in turn is 5 gallon / 19L. But nobody says "My 19L water jug", they they just say "My water gallon".
replySince most people in Indonesia get their drinking water from these jugs, stating this filter's output in "gallon" terms is just the easiest way to communicate potential savings etc (since people pay per jug, so they think in jug terms, not in any other unit of measure).
