Regardless of if my thoughts are right or rambling with the pump 1/4 or 3/8 is more than enough for 150GPD.
I noticed.
My RO is off since I don't do fish anymore.
My output was visible so I would have know if it never stopped.
My house pressure is not great also which I would have thought meant nothing but who knows.
It is the sole purpose of this part.
Installation Instructions 1/4" Automatic shut off valves are used with float valves or pressurized tanks to shut off an RO system. It utilizes the back pressure created by the float valve or pressurized tank to shut off the water supply to the membrane. Without an automatic shut off valve...
www.bulkreefsupply.com
With out it I can see nothing completely stops water from going through the TFC and going to waste when the float is shut.
I remember you got one installed and still no bueno though.