I have the same setup as 82cabby, but I have 5 membranes. I run the system typically 100 - 120 psi and process about 10 gallons of sap/ hour. It's slow, but I generally run it while I'm sleeping. I have found it runs a little faster if it's warmer. Based on 10 gal/hour and how many gallons of sap I have to run, I set up the power on the pump to a timer and let it run and stop automatically. I typically run it through twice and have had good success with 3% sap getting to 11 - 13%. I did find the quality of the membranes to matter, the dow filmtec ones were higher % than whatever cheap ones I got last year.

On timing - I boil once/week and try to run the RO once/week unless I have a lot of sap to run. Generally I try to run the RO the night before I'm planning to boil. Typically Friday night for Saturday boil. I think the biggest amount of sap I had to process was 250 gallons or so. Towards the end of the season the filter clogs up a lot more often and I have to change it frequently to keep the pressure up. The concentrate (especially at the end of the season) absolutely spoils faster than sap. I keep it in the garage so above freezing but not warm, then run it the night before so it has minimal time to go bad.

None of my ideas are new, this website has been amazing for keeping production up despite not having a properly sized evaporator for the amount of trees I tapped: https://sites.google.com/view/mattat...sis?authuser=0

Cost me about $500, best thing I could have done with that money. the RO is a huge time saver.