The DOW engineer that I talked with explained that there it is more efficient to run at higher volume and lower pressure to get the most consistant product and longest life from the membranes. The old technolodge vs the new in membrane has changed and the xle is designed to provide good rates at lower pressures andadd to membrane longevity.

I got to talk to this guy because I was having an issue passing sugar and he explained that running at higher pressures there were several issues that would arise.

I did a couple of the tests he gave me to test the efficiency of the unit and he was right. Less energy used at lower psi and more product thru the system for the cost. I found that running at 250 gave me the most return on investment and the unit ran cooler.

While doing the recommended tests I got upto 475 without sugar passage but the energy usage in amps nearly doubled without doubling the output.

Point of diminishing returns was his key factor. When you are putting in more energy and not getting the same return percentage wise you have passed the point of efficiency; and the ware and tear on the unit brings that point lower yet than just the energy factor.

Take your car...if the fuel mileage was the same at 80 as at 60 why not drive 80 all the time...then factor in the added cost of the inevitable ticket, the safety of you, passengers, and by standers and it is a better return to drive 60. Now factor in the reduction of the fuel economy at 60 and it really pays to drive 60; but the car can do 120.

But on the other hand if it is 11 pm and the sap is flowing good...you better believe I am going to to have that unit cranking to keep me from having to stay up til 2 am so that tanks will not over flow in the morning and I can get some extra shut eye time. Sleep time is very valuble to me. When I am tired things seem to go wrong a lot quicker. Funny how 4 hrs of sleep doesn't cut it any more????

Ben