RO/DI Help

[hillegom]

They should always come with one. But sometimes depending on manufacturer, they are hidden in a fitting, like an elbow or a connector. Not familiar with the AQUA FX barracuda.
Start at the drain and work backwards. I have seen one where there was just another piece of hose stuck in the drain hose, close to the unit. So there was about a 1.5-2 mm opening that the drain water has to pass through which puts back pressure on the membrane, and everything works perfectly.
Either yours is missing or faulty. IMO