How much waste water does a RO unit produce?

[Bloodasp]

mine makes about 1 gal RO for 3 gal waste. tried calculating how much it would cost to with filters and membranes and waste water hopefully I got it right, it costs about $0.80 per gallon of RO water produced. biggest cost comes from the RO membrane.

[Wayne]

Hum well I guess I will have to plumb a line into the sink drain. I was originally planning on putting it into a bucket, but after I make 5 gallons of water and have 20 gallons of waste, esshh! Thanks