So 1 issue I did find was that these valves are normally closed and I needed 1 closed and 1 open for each of my scrubbers but I could not find normally open valves that work like these. So I end up modifying 2 of my 4 valves so they are normally open. Did this by separating motor from valve body and used a dremel tool with cut off wheel and made a slit in valve body so motor can be put back on with valve in open position. Sounds complicated but was very easy. Please ask for more info if and when you are ready to do this and I can walk you thruWhat size tubing are you using? 1/4 inch is pretty small the same size as the neptune solenoid.