[charlie2]

Hi got a 4040 and keep hearing differant storyies as to how fast the waist is running out at herd today someone runs 70 waist 30 good water does that sound right?
  regards chris

[AJ]

there are so many differences accross the country with regards to water pressure, TDS of tap water etc, its basically trial and error.
Start off with your waste water 3x your product, and gradually reduce the waste till you get the optimum TDS. don't just turn the valve a bit and test, turn the valve a bit, wait a couple of mins and then test.
My tap TDS can get to nearly 500 and whatever I do, I cant get the water after RO below about 18. With a booster pump I probably could. Waste runs at approx 50-50.

[concept]

do all systems have a waste control?!

[chris@c.m.s]

I have found with my pumped 4040 if I try and keep the waste minimal the tds rises, the lowest tds I can get from mine is about 5 and that's probably about 3-1 of pure.
I tend to go by the pressure hitting the membrane now though and mine works best at about 110 psi and I'm getting a tds of 7.   

[pingu]

I start with aprox 260 tds with a 55psi and get around 5 tds after the membranes....this is umpumped and a HF5-4040 membrane.

Cheers
Dave.

[charlie2]

Thanks guy most helpful

[R W C]

Tds tap   280
system, salt, softener, filters, ro, then its down to 001
pressure 75