How important is the DI stage for shrimps?

[Vic]

Hello. In my previous aquariums I had very soft water so I had to add salts to get the TDS GH KH for my crystal bee, now I'm living in England and the water is very hard so I need a RO system hence my questions? How important is the DI stage in filtration? Is it fine if I take any RO system not clearing completely the water down to 0 ppm lets say getting 50ppm and add salts to get the 170ppm ? Is it a goo idea to buy it second hand?
Thanks a lot

 

[kirk]

I use mine to clean my windows too so I opted for the di too. I also wanted it to leave my unit at 0ppm, with no possibilities of anything other than what I add to water irritating our crs. I'd got for it personally if you worry like I do. I did buy second had but it was all up and running and not hadn't,been left off to dry out, when I tested the water it was leaving the unit o ppm so I ripped his arm off.

 

[Vic]

I did buy second had but it was all up and running and not hadn't,been left off to dry out, when I tested the water it was leaving the unit o ppm .

Hello Kirk
What if the system has been disconnected for lets say 1 month or 2? Wold it affect the working quality and the water output ?