The sewersolution won't shoot any water into your system unless you want it to. It depends on where you set the valve position. Normally, it just pulverizes the waste so it's in a more liquid form. Roger Roger Hightower, N7KT WBCCI 4165, VAC, TCT 1975 31' Sovereign, '02 F-250 PSD Mesa, AZ mailto:n7kt@att.net