RO/DI unit from Captive Purity question

[newreefer_59]

I have an RO/DI unit from Captive Purity and wondering if anyone knows if it is ok to shut off the water supply to it when it is not needed. ie: when my reserve tank is full. I ask this because of the amount of waste water that draines even tho there is no water flowing into the reserve...is that normal? And would shutting off the water supply but leaving water in the unit have any adverse affect on any of the filters and membrane? And is there a toll-free support line for Captive Purity?

Thanks!