I am just setting up a used external RO skimmer. It seems to run fine but sometimes it seems to lose the aeration from it's flow (or the impellar is skipping or something). I can hear when it's happening which makes me wonder if it isn't the impellar. But if I watch the flow into the chamber it goes from white (due to bubbles) to clear... which implies to me water is still flowing it just lost aeration. Here's a video of it... not very good quality: https://youtu.be/sKhv6MlvrfE. You can't hear the noise that accompanies the loss of bubbles but it's basically a low rumbling. Anyone have ideas about what's going on?
