Is it possible to add to a Deer Run 250?

[maple flats]

I'm wondering if I could expand my Deer Run 250? I could quite easily add 2 more 4x40 posts but could it work? Would I need a bigger HP pump and can it still be done with 1" supply connections. I realize it would not change a 250 into a 500, but I have 2 spare membranes. What if I hooked 2 more in series with the existing 2, might I get a 325 or even a 350 performance.
Ideas please. I could change to existing HP pump and use a bigger electric pump for greater pumping capacity if needed.
I studied the framework and I could move the wash tank away from the 2 membranes enough to run 2 more along the side where the wash tank is now bolted and I could rework the support frame on said tank. After that it would just be a matter of plumbing. Could I gain from this?
My thinking is that using the existing pump I'd still have a 250 gph RO but I might be able to remove 50-75% more permeate at a time even though the pressure might run lower because the pump would then be pushing thru 4 membranes instead of just 2.
What is the error in my thinking?

[WVKeith]

Dave:

I have a Deer Run 250 that I just upgraded from a 125. When I am concentrating raw sap without recirculation, I get about 3.0 gpm permeate and 4-5 gpm concentrate at 275 psi. So that is the limit of my pump at 275 psi, 7-8 gpm. Disregarding the pressure loss for concentrate flow through another membrane (<50 psi). With another membrane, I would nominally expect 4.5 gpm to permeate and 2.5 to 3.5 gpm to concentrate. The problem here is that the flow past the membrane may be getting too small to keep it flushed. That would just get worse with a 4th membrane. Of course a bigger pump and motor could up the flow rate. This is the way I would analyze your proposal

Keith

[wiam]

Not sure how yours is plumbed. On my old memtek 250 the 2 membranes were in series. I added 2 more in series but parallel to the first two. This machine had built in recirc using the high pressure pump. I valved between membranes so I could run either pair or both. I was getting close to 375. When washing I would alternate between "sides" to get better flow over membranes. Seemed like it would wash better.

[MISugarDaddy]

Dave,
Have you checked out your idea with Ray? Back when you and I got our units, he was building a 375 and I think a 500 units using 3 and 4 membranes respectively. Maybe he can offer a suggestion.
Gary

[Wolfcreek Maple]

I just talked to Ray the other day about doing same thing to my to 250 he told me the pump is not big enough and all I would gain is extended run time without fouling the membrane .