Reason I say so, is because we have a water softener which treats the water as it comes into the house. The only water which doesn't go through it is the garden hose and a separate drinking water tap (I much prefer the taste of hard water). Said softener keeps a minute by minute log of the water use. The main water meter is an online jobby out in the street that gives daily readings.
My water meter and the softener disagree to the tune of 50-100 litres per day. I can't imagine I'm using that much drinking water! I can see the days where I wash the car, which is the only major use of the garden tap, but other that I can't account for those extra 100 litres.
Short of poking around trying to find a wet patch (
