RO/DI machines

[bald57]

Hi all.
I have been looking into getting an RO/DI unit. I have heard that for every gallon of good water, you dump 4 gallons in the drain. Is that true. If you loose that much water to the water treatment plant for what you get, is it really cost efficient when you factor what the water from the town costs.
How cost efficient is it really. Right now I can buy RO/DI water from a local supplier for 1.99 for 5 gallons. Any thoughts on this?
Thanks Bill

 

[Keithhjs]

You can add a second RO membrane & cut your waste water and increase your product water. With the right pressure you can get 2 gallons waste to 1 gallon product, or 3 to 1 respectively. Also by having your own unit you know how often your filters are changed & if you have a TDS meter you know that. You are then in control of what you are adding to your tank.