Installed an undersink RO unit. Water tastes great and evidently helps out my beer...
Problem is this unit is only about 9% efficient according to the manual. For every gallon of RO water produced 5.5 gallons go down the drain.
This has been measured by myself several times. If I had realized this beforehand I might have done something different. Plus the runoff is about 310 ppm salinity- only about 30-60 ppm more than my softened tap-water.
I'm not about to stop using it now!
Thought about drilling through the wall under the sink to the outside to run the waste into a collection tank or into a solar still. Then this water can be used for my garden.