I had a problem with low pressure coming out of the faucet from a Proline 5-stage RO unit. I drained the tank, pressured it to 8 lbs, hooked it all up, and turned on the water. The water has been running from the unit to the drain through the red plastic pipe for more than 2 hours. How long should it run to the drain. When does the tank fill and how long does it take?