I used 26 litres of water and added 3 litres of sparge at the end... I still came up around 3 litres short though at the end. It was a 1.060 gravity Pilsner in the end and the lager yeast has started to get going so I will drop it to 11 degrees for a couple of weeks and see how it turns out.
The BM is incredibly stress free... fire and forget

All in all very happy indeed. Next up will be one of the original IPA's I devised that I am hoping I can replicate reliably and license in future.
Jeff