Thank you, I will try that. Regarding the Polaris, its a 360 just bought it a few months ago, the old one died. Anyway, I've tried all the adjustments recommended and it still wants to keep surfacing, was thinking maybe the blue cover was airtight and holding an airpocket, held it down to purge it, still floats up, seems that the debris bag forms a bubble and the jets just keep pushing it up. ??? thinnking of drilling holes in blue body to accept more water, ?? also backup valve seems to have gone kaput,,,