Lifeline Anjon ADD-8-8" Pond Aeration Micro Bubble Membrane Diffuser Disc 8" Diffuser disc produces high oxygen transfer micro bubbles to help keep fish healthy and ponds clear. Increases oxygen levels for healthy and happy fish. Promotes growth of algae-controlling beneficial bacteria. Lowers levels of dissolved toxic gasses and ammonia. Reduces sludge build-up on pond bottoms. Helps maintain an open-water hole in the ice during winter to release trapped toxic gasses.