I purchased my rodi unit used about 8 months ago. I have well water so I attached a booster unit (CDP 8800) I purchased online. All filters were purchased at BRS. The RODI is a 4 stage plus a DI. (Just as a side note: I never hear the booster kick on. Maybe it does when I am not in the area.) I just added a gauge about 2 weeks ago which is what made me decide it is time to change my membrane. The pressure read 20. My original house pressure is about that amount! I also found my tds was off so I figured I would just change the sediment, carbon and DI and see if that would change my water pressure. It did not so, I went to menards and purchased a new membrane. I have my rodi attached to the bathroom piping. I turn on the on/off valve to access water for the rodi, so it is not always on. I then start my booster and let it run until I get the amount of water needed. Anyway, after the filter change, I turned on the water and the pressure went up to 30. I did not open the rodi flush valve yet. I turned on my booster but it did not kick on. I turned the flush valve open and the booster kicked on but the gauge registered 0. Unsure what is going on. Any help would be appreciated...