Ours is even smaller, .75L or .2 gal. Iím happy with this size as it nicely smooths out the pressure flow, eliminating the spurt-spurt-spurt that a straight water pump delivers, as well as dramatically quieting pump operation. We didnít install the accumulator to eliminate pump actuation, yet find it does reduce it quite a bit. Not as much as yours though. I havenít measured how much water is delivered between pumpings, but itís definitely far less than 16 oz. But with the acoustic damping and the smooth fluid flow, I find I donít really care how often the pump runs now, as itís so quiet that I have to strain to hear it at all and any ambient noise overrides it. Iím sure various mounting methods produce varying results in this regard.