[canadawest]

Hey Chad, welcome to the world of RO/DI creation!

Yes, the yellow discharge hose is supposed to be constantly flowing when the unit is processing water. If you have your unit permanently plumbed into a water line, then you will need to have a shut-off valve on the intake hose (usually black) to prevent the unit from constantly running and processing water.

Typically the waste line (yellow) produces 3-5 times the output of the processed water. So for every 1 gallon of processed water produced, there is typically 3-5 gallons of waste water. The ratio depends on several factors, water pressure, temperature and TDS of the input water.

HTH