I asked a few questions on another thread that got me going this direction. I figured I would start a new thread to hopefully help someone in a similar situation.

I have a 1 membrane 4x40 currently while trying to do about 1200ish taps. I let it batch run up to about 8% then add another load of fresh sap to flush and do it again. The bad boy will run almost 24/7 during peak season. Full time job limits time spent boiling but when you have sap you boil. Many nights I got 3 hours of sleep and sometimes many in a row. Tempers were running short till the end of season. Things MUST improve till next season. Budget is tight with 7 kiddos and a new or even decent used commercial ro is out of my price range.

Game Plan.
With my current rig I can simply add 2 more membranes with minimal cost. My wife homeschools and can help out running it while I am at work so we can still just batch ro as we are. With more membranes my output concentrate will be a higher % and time running ro should decrease saving some frustration and electricity $.

1hp motor to 1 1/2 dairy releaser style pump. Getting rewired to 220v to help amp draw.
2x20 prefilter to 330 Procon on a 1hp motor also to get switched to 220v.
4x40 MES membrane to needle valve and a flow meter on both concentrate and permeate side.
NO bells and whistles. That's it.

1. Any concerns with the motors/pumps keeping up to adding 2 more membranes?
2. Any need for flow meter on each membrane? I don't see much value in this setup.
3. How can I add a low PSI switch? A constant concern is something running dry or a pipe freezing causing pumps to burn up. We check on it often, usually never more than a hour passes but life happens and I would like the assurance.
4. I still only need 1 needle valve at the last membrane correct?

Hoping I can make this work for a few years till the bush is all setup on vacuum and good to go. At that point we can start to work toward a commercial RO. Thanks for any feed back as always. Stay healthy everyone.