>...tried an airstone in the CO2 generator... Thanks, James. I just squeezed the sides of my moribund CO2 generator to create a steady stream in the pump venturi, then slightly unscrewed the lid and relaxed the sides. It sucked in air, I closed the lid, and within 30 seconds it was producing 2-3 bubbles a second. Yeast need oxygen too! Cheers Charlie Charlie Lear Melbourne, Australia