Forget ratios. Focus on the contents of that source ppm. Why I used a pound of salt as an example. Can’t produce more salt than source provided regardless of what ratio that waste ends up being.What’s your ratio of processed to waste water? If you’re is 2< : 1 you are correct. The standard is more like 1 : 3-5
The membrane will direct all the salt to waste. That waste water just had a greater concentrate but not a greater amount of salt. Can never be more than the pound provided. Why 100ppm equal 400ppm in one quarter the volume of water. Still represents one pound of salt.
If one pound of salt in 4L of water isn’t detrimental then neither is one pound of salt in 1L. Still one pound of salt.