Testing 4x40 Question

[Dfarmer5218]

Got dechlorinated water to test my new 4x40. What pressure can you achieve with just plain water. I was able to get over 100 psi with the concentrate valve closed almost all the way. With an xle-4040 what pressure should I have?

[maple flats]

I never tried getting high pressure on just water. It likely will not really test the RO. However it will clean the membrane(s). Try to crank the concentrate valve to where you get 3x as much permeate as concentrate, maybe even a little more permeate than that. Then save the permeate and dump the concentrate. After you have finished the start up cleaning use the thus gotten permeate to rinse the membrane and you will be ready to concentrate sap.