Every process that happens in the pond is dependent on oxygen. This is especially important at night when your pond lights don’t provide the necessary light for your plants to convert fish-created CO2 into oxygen. Dissolved oxygen levels are also generally lower in warmer water temperatures. Pond aerators and pond aeration systems oxygenate your pond, helping create a more stable environment, resulting in healthier fish and plants.
There is people out there, they say you can over oxygenet your pond, don't get fooled by them, water holds only a amount of oxygen, everything more escapes into the air! You Can not over oxygenet your pond, that is simply impossible!