the "red line" is waste water coming off you ro/di unit... it means waste .
DO NOT mix your clean purified water with the waste.
or your on a "refillible" well ? , yes i should see no reason why you couldint put it back in your well to run thrue the ro/di unit over again.
the ro/di unit works under pressure any way , water that makes it past the filters with out being filtered only go's to waste, in your case though , your able to retreive actualy ( really saves wasted unfiltered water consumption ) |