On Sun, 27 Nov 2016 14:10:34 -0000, Phil L wrote:

If you can't see any damp patches or pools of water indoors, then the water
is going outside. If it needs topping up daily, you couldn't possibly have
missed an internal leak as it would amount to a small bucket full every day.
As others have said, the water is being expelled outdoors via the pressure
relief valve.....and I find it impossible to believe that BG didn't already
know this

There is also the possibility of discharge from a joint into the
earth, as we have suspended timber floor about half a meter off the
ground. It is a lot of water as you say - hard to miss.