[andyralph]

hi all looking at up grading my system looked at daqua at the 4021 or the 4040 any any body tell me which would be better for me i use approx 3000 litres a week and what is the difference between the 2 systems my merlin is on its way out thanks andy

[andyM]

A 4021 will likely be a bit cheaper to buy than a 4040.
But the 4040 will produce water much faster.