Pressure dropping as membranes become plugged.

[heus]

With my previous 2 ROs (Deer Run 375 and D&G 600), as I processed more sap and the membranes got closer to needing a wash, the pressure would climb and if I kept it going too long, the high pressure switch would shut the machine off. With my Leader Micro2, as more sap is processed, the pressure actually drops, and the concentrate output increases. Is there something wrong with it, or is this how the Micro is supposed to function? FYI, there is no high pressure switch on it.

[johnallin]

First year for me with an RO, so no experience there, my CDL hobby 100 also has no high pressure shutoff.
As it processes more sap the permeate flow drops and the concentrate seems to increase.
Pressure gauge will rise though, from 150 when clean to 175 when it’s getting plugged.

[Urban Sugarmaker]

Maybe your pre-filter is plugging and dropping the feed pressure to the membrane? If so, your permeate would would drop and possibly your concentrate flow would increase. At least in theory. When I reduce pressure the concentrate flow increases and permeate decreases...low pressure, high flow.

[heus]

I can see how that theory could hold true. It does have low pressure shutoff but I could still see this happening.