RO system set-up

[sparkey]

Need some help setting the flow rates on my RO system. It has one 4 x 40" membrane. What should the flow rates be for the product flow, reject flow, and recirc flow? I read somewhere that a 4" membrane needs 3 gpm flowing across the membrane to flush the solids off. The new membrane I purchased is 2400 GPD.

 

[MEP001]

I don't know if there's an ideal setup, but when there's a portion of the reject returned to the pump the product and reject should be the same. The systems I've worked on have the pump sized so with it at 200 PSI and about 1.5 GPM of product there's about 1 GPM recirculating.