[L.J.Thorpe]

they have different outputs some i have seen are 80psi some 125
is there an optimum output to suit particular systems
i have an RO man 300gpd
cheers for any advice

[martinw]

as far as i am aware there are 2 different kinds. all dependeds on max psi rating of ro membrane(s).  it should be written on the label on your ro unit. you should be ok with 125 psi just double check. i'm using aquatec. it went from 25l/hr to 47l/hr with pump 300gpd ro. waste ratio 1:1 more or less. hope this helps

[L.J.Thorpe]

i get about 25 ltrs an hour now its the tds that i am more concerned about
in to ro at anywhere between 430 to 480 and out of ro at about 44
gonna borrow a mates pump at weekend and try before i buy