I want to produce 600-800 litres per day. Whats best ro unit and how quickly does it take?
if you are wanting speed you will want a 4040, the other are slow, also if you get a problem with the slower ones they take time to start producing what you need per day.
With a boosted 4040 you would be doing 600L is about 2 hours leaving you time to enjoy other thing apart from waiting around