Can anyone tell me if this is normal for large bubbles to come out of my returns each morning after the pump has been off overnight? Now I do have a Ozone generator however the bubbles that come out are very small when the pump is running. In the video you can actally see the small bubbles but then you see the large bubbles for about 5 seconds. Here's a link to the video; http://www.youtube.com/watch?v=p7CTPO-1xVE

Thank You!