For the guys running a two man setup what sort of water are you going through. Ideally would like to know amount of houses and average size. I know it's like how long is a piece of string but was chatting to another we last night and it seems a 650 tank is fine but you will run out. When I asked him about amount of houses he was doing far less than when I work with another wc albeit a new wc or a vet. I know noddy uses 1200L Other guys ?