Older osmonics maple ro will do around 800gph /- depends on the sap and how hard you want to push it would probably go higher i never push that hard great working unit new membranes 2 seasons ago xle 4x40's have all the original manuals and service records name plate state flow around 600 but it has had 2 additional membrane vessells added any unanswered questions feel free to call or message me 814-964-1124 GREAT RUNNING UNIT VERY HAPPY WITH IT JUST LOOKING TO GO BIGGER IF I CANT SELL ILL CONTINUE TO RUN IT