[scud]

  If the tds in is approx 540ppm, the water pressure is 25-30psi, what sort of tds reading should I get after the filters, but before the DI resin?

   I ask as it is only getting it down to 30ppm, whereas the old RO would get it down to around 2-8ppm.

[smearo]

scud i have a merlin psi 26... tds before ro 280 after between 50/60.. di polishes of last bit..

[scud]

 Surely this is going to use alot of resin?
 
  It's not going to make viable financial sense, the 4040 is not mine, I still use my old RO, my mate has got this new one, it produces plenty of water but the tds seems high before the DI.

[smearo]

well i personally cant win i have low psi high tds etc etc but from what im learning there is way round things ie booster pump etc etc do plenty of searchs

[pingu]

Hi...I have a HF5-4040 into a 20 inch sediment>carbon filter...then into a di vessel..

At around 20 deg my tap water which can range from 260 to 300 normally produces between 5 - 11 tds at around 55psi.

A booster pump would certainly enable you to lower that tds after the pre-filters.

Remember that a 4040 and a ro-man type system will handle the water differently with regard to volume and speed of production...they both produce water but differently. My 300gpd ro system would bring 262tds water down to 0 or 1...all year long despite temperature differences...

If you are seeking alternatives with regard to speed/tds/ input/outputs..speaking with June at GAPSWATER may not be such a bad idea...she really knows her onions.

Cheers
Dave.