RO systems & flow restrictors

[Doug]

Originally Posted by Myka

My flow restrictor is in the waste line where the line attaches to the last filter cartridge which in my case is the DI.

I think 3g waste per 1g good water is too good to be true. I think mine is more like 4:1 or even 5:1, but I've never officially measured it.

Why is the waste line going to the DI ? Do not all waste lines go down the sink or where ever?