One last thought/ If the feed ...

One last thought/ If the feed pump were moved to the discharge side of the RO system, a recirculating line could be used so that only the one pump would be needed. Instead of the pump discharging into the fresh water system, it would discharge into the inlet side of the RO system until the primary discharge valve is opened and the recirculating valve is closed. It's suction would be taken off of the RO system and a fresh water tank when the system is being started. And since the water would be circulating in a loop, it's operating pressure might be less than normal.