This is how I set up my system. I used the pressure as an indicator incase my bypass valve got move. The flow restrictor of the smart buddie is only rated at 100gpd, so with this 150gpd set up I get .75:1 ratio but higher TDS. So I am adjusting the openning of the bypass valve and compare TDS at different waste ratio. Right now I am at 1:1 and TDS is 10, pressure with this ratio is about 70psi. If I open it more to 60psi, ratio is 1.5:1 and TDS is about 9. So for me 1:1 is more cost effective.