Hi all
we run our system like this;
1)water in from mains-normal pressure but high tds, nearly 300
2)through Harveys water softner-that way the house is getting lovely water too(the Harveys rep{one of my customers BTW} installed a system that can cope with the demand we place upon it,as they installed one at the local McD's)
3)Boosted through to R/O-supplied by streamline
4)R/O system from streamline(2 x membranes and 3stage filtration)
5)Large DI -robbed of our Brodex 650
1000 ltrs per day,no problem and very,very consistent low tds(never higher than 001)
haven't changed a membrane in 10 months but filters every 3.No resin change in over 6 months
We monitor every day and its all good
Hope that helps
regards
Roy