TDS readings questions

[Jay357]

Hello:
I got a new membrane today from Filter Direct. It is a 75 GPD membrane and looks to be working just fine I think. After 3 hours making water I am getting 5 tds after the membrane before the DI resin. I have not tested it after the resin but Im sure it is zero. Question is , is 5 TDS after a new membrane is installed ok? That is measured at the outlet of the membrane before it goes into the DI chambers.

Thanks
Jay

[Loverotties]

Yes the Di polish the water down to 0.

[Kimberfish]

I have an RO/Di that I replace all the filters and membrane on and was still getting a reading of like 11 so I added another DI cartridge and now I"m finally getting 0. Never did figure out why mine never read 0 after the first run thru 4 cartridges