We have listed above all major manufacturers of koi pond air pumps. Within each manufacturer we have grouped their air pumps by size or Liters Per Hour (LPH) or Liters Per Minute (LPM). Some pumps from the same manufacturer, that are similar in size, are reviewed together.
A koi pond requires a constant supply of fresh oxygen to be introduced to the water. Every living thing in the pond will struggle to survive if the oxygen levels are too low. Not just the koi, but also the beneficial bacteria you are growing in your biofilter is highly oxygen dependent. If oxygen levels drop to low then the filter will be less efficient.
Regular testing of the oxygen levels, especially during the warmer months, is the best way to determine if you need to add additional oxygen to your koi pond.
There are many ways to add oxygen. Waterfalls are always a beautiful choice, also spray bars, trickle towers and spitters can do a very good job. Another very effective way it to use an air pump. Air pumps not only add much needed oxygen to the koi pond, but they have the added benefit of improving circulation in the pond. Air stones can also be added to certain types of filter systems. For more information on aeration in a koi pond, read this article on koi pond aeration.