How much Sodium (Na) is too much?

[Common Sense]

Hello,
when growing cannabis in soil, what in your opinion and experience is the max water sodium (Na+) content tolerable?
The house I live in has an ion exchange system to prevent water pipe and device calcification. Ca++ and Mg++ ions get exchanged for 2 Na+ ions each. The filter ist regenerated with NaCl.
At the moment the system is set in a way that results in a Na+ concentration of around 115 mg/l (about 5 mmol/l). The EC is about 525 µS/cm = 0.525 mS/cm (same pre and post filter). One can definitely taste a difference pre- and post filter. I am worried that >100 mg/l is too much for cannabis.
I do have access to pre-filter water. It is manageable, but it is a bit cumbersome.
I am trying to find out whether I need to mix pre- and post filter water and by what ratio. If I need to get an osmosis filter it would have to be one with an additional pressure pump due to lack of water pressure (okay for normal life, but less than 2 bar is not enough for a standard RO system. I know from my aquarium hobby times). I am a bit limited in space and a large RO unit would raise issues with wife.
Anyone have any experience? Different strains might have different tolerance levels...
(sorry if this is the wrong forum, moderators please feel free to move)

 

[exploziv]

I would totally use prefilter water or get a r/o system. And even with a r/o filter, using tap water and not salty water as your starting point might be better for your filter life. Clean water is the best carrier for nutes if you want to feed them a certain recipe and not have all the "noise" and imbalances that tap water brings. Unless you check your local posted water analysis and you find out what's in there and ratios they are in relative to one another is useful enaugh to not filter it out.