Pond Aeration – Critical For Healthy Fish

Pond aeration can be critical for keeping your koi fish healthy. Your water garden pond gets its required oxygen from two different sources: diffusion and photosynthesis. The most significant source is photosynthesis, the process from which plants prepare food. Plants add oxygen into water as a result of photosynthesis, in the presence of sunlight.

During the night, oxygen is not produced, but the respiration of fish, bacteria and algae keep on removing the oxygen from water. Mostly there is a good balance in the oxygen produced vs the oxygen used. However in some conditions, if the balance is not maintained, the level of oxygen can become very low and may stress or even kill the fish. Pond aeration is used to prevent this oxygen depletion.

You can use either mechanical or electrical pond aeration. This is generally done by mixing large amounts of water together with the oxygen in the atmosphere.  Many different types of pond aerators are available on today’s market. Some of the aeration equipment that are used for pond aeration are electric paddle wheel pond aerators, electric pump-sprayer pond aerators, electric propellers, aspirator pump pond aerators and experimental pond aerators.

Aeration Methods
Pond aeration devices should be placed along the longest bank of the pond. As a basic rule, 1HP of electric aeration is required for every 4 acre-feet. Pond aerators must be started before the DO (dissolved oxygen meter) moves below than 3 mg/l. The level of oxygen will be the lowest just before the sunrise. If it is affordable, then it is better to operate the pond aerators during the night for a prolonged period of two to three days when the weather is hot, rainy or cloudy or when there is rapid development of algal blooms or phytoplankton.

1. Emergency
Pond aeration should be operated whenever the oxygen level falls below or to 3 mg/l, as a temporary measure. The tractor powered irrigation pumps or paddle wheels are used during these kinds of situations. Aeration should be continued, till the oxygen level stabilizes to 5 mg/l or higher.

2. Supplementary
Pond aeration should be operated whenever there is situation where the oxygen depletion has started. Pond aerators can be turned on between ten o’clock in the night till ten o’clock next morning or till the oxygen level reaches a stabilized measure of 5 mg/l or higher.