Pond Boss Forums GENERAL QUESTIONS Help Imminent Fish Kill ? I am in trouble!

The largest fish in the pond consume the most oxygen. Sometimes fish are not smart enough to move to areas of the pond that have more O2.

Shooting the water out into the pond from the well helps, but the best way to oxygenate the water that I've seen is via a packed column like Cecil uses:

http://forums.pondboss.com/ubbthreads.ph...ite_id=1#import

It's not the prettiest thing, but function outweighs aesthetics.

O2 levels ebb and flow in a pond, with the lowest levels occurring right before or at daybreak. If you don't do something to add O2 to the pond (like an aeration system) that adds O2 during the pond, expect this to happen anytime that the biochemical oxygen demand is greater than what the fish need to survive, even if there is only 1 fish in the pond. It's not only fish that need oxygen, it's all the plants, algae and bacteria in the pond too, whenever the sun isn't shining and photosynthesis is not happening.

As a pond gets older and older, the BOD increases due to the organics that make their way into the pond.

As I see it, you have 2 choices:
1) Reduce the BOD of the pond.
2) If #1 isn't possible, then you have to add a properly designed aeration system and run it enough to keep the O2 levels up. If you don't have a way to measure that, I would run it 24/7 when water temps are over 70�F and when there is ice and snow on the pond.