Aeration
Proper aeration is critical to a fish pond. The fish as well as the beneficial bacteria require oxygen to survive and flourish.

Aeration can be accomplished through waterfalls, fountains, venture jets, etc. Supplemental aeration can be added using air pumps with air stones or disfussers. This is extremely beneficial especially during hot weather when ater temperature is high and oxygen levels are low. Also, if you have very large fish, supplemental aeration is highly recommended.