What is the max back pressure on a RO unit

[TheReefGeek]

The manufacturer should be able to to tell you, if not test it out and see if it works.

I know my setup runs about 30ft horizontal with lots of bends, so there is some head pressure there and it works fine.

[Paverdude]

My RO feeds into 3 preassure tanks that are pressurised to 40 lbs, so there should be no prob