If you have an RO or RODI unit you know what I am talking about. I use mine to water plants in the house in the winter and outside in the summer for my garden. So, what do you do with your waste water??
I dump mine down the drain, Called recycling. My septic system cleans and reinserts waste water back into ground as clean as it was coming out of faucet.
When I was still running FW tanks I used to just let the waste line dump straight to the sump, and let the emergency drain on the sump dump the extra down into the drain.
Saved me the hastle of the extra water changes. These were heavily planted tanks, and they had some awesome growth with the waste water. Nearly everything was constantly pearling.
Someone mentioned to use it to refill the tanks on the toilets. LOL
I am going to run a discharge line outside under the mulch for the plants this summer.