The poor chap with the fish die off in Illinois said, where the bubbles reached the surface, the sulfur smell was overpowering. Eventually, as you work deeper into the water column, the stone and bucket will come to rest on the bottom. At this point, the rising bubbles will serve to pull water from the bottom layer of water, but not the sediment. This is prevented by the bucket. The anaerobic sediment is laced with bacteria producing poisonous gases.
Aerobic bacteria are the good guys.
They breathe oxygen like us and exhale C02 like us. They have a tremendous appetite, eating anything organic, and quickly. Given oxygen from the diffuser stone, the aerobic bacteria begin to eat the organic sedirnent at the bottom of the pond, and will continue to eat it as long as they are given oxygen. Aerobic bacteria also eat the dead anaerobic bacteria, eventually eliminating all the anaerobic bacteria in the pond and making the water fresh from top to bottom. All rights reserved.