making pure water

[Mooghy]

just got a RO and a DI system, i have quite a high pressure mains in my house can i just use the water pressure into the system or should i also have a pump??

 

[ched999uk]

Depends on the membrane - some will work efficiently as low as 50psi.
Do you know your tap pressure and what membrane (make, model and size) that you have?