Did you know that when oxygen levels in the pond drop, that the biggest Koi are effected first? It is a fact. Their massive bodies in comparison to the smaller fish in the pond consume much more oxygen. The lack of therefore, causes them problems first.
Some of the key components that assist in the decrease of the Koi pond’s oxygen level are:
- Higher Temperatures – When water temperature rises, it simply cannot hold the gasses that are usually trapped in it. This is not only true for oxygen but for all gasses like nitrogen and carbon dioxide.
- Contaminants – Any sort of contaminant including an over abundance of fish waste will also cause a decrease in oxygen levels. This is why it is so important to monitor water chemistry on a regular basis.
- Poor Water Circulation – If you are not moving enough water in and out of the pond to be filtered, the lack of circulation will cause contaminants to build, which in turn decrease the oxygen level.
- Salt – Yes, salt is used in certain quantities to help aid in the fight against parasites and such, but the salt level will also assist in decreasing oxygen levels.
Aerating the water is as simple and providing a way for the atmosphere and the water to mix. Water flowing from a waterfall into a pond or the use of air stones or other devices will make this mixture happen.
You might think that the mixing occurs when the bubbles are under the surface of the water, but this is not true. The actual mixing process happens when the bubble burst on the surface of the water. So having not enough bubbles or bubbles that are too large only make the transfer suffer.
This is why it is preferable to have the air to water exchange happen with an aeration system from a device like and air pump rather than just rely on the exchange made by a waterfall.
More oxygen in the water will also aid in the growth of good pond bacteria. This is especially true at the beginning stages of creating a pond. At that point you want to encourage a lot of bacteria (good) growth for your biological filter media.
Have you ever noticed that some pond keepers have their aeration system set just on top of the drains in the very bottom of the pond? Because the water is being drawn from the bottom, this aeration system will circulate the pond’s total water column better.
You should never think that just because fish can breathe in water that they actually have enough oxygen to breathe. This is a mistake. Fish need oxygen. Good bacteria need oxygen. It is your job to make sure that they always have it.