Know More About Fish Co2

If you have a fish pond, it is essential for you to know about fish Co2. Apart from the atmosphere, co2 is present in the fish ponds as well.

The main source of Co2 in fish ponds is the process of respiration by the fishes and other microscopic plants and animals of the aquatic life. Decomposition of the organic matter also releases Co2 in the ponds.

The pattern of carbon dioxide concentration is opposite to that of oxygen concentration in a fish pond. During the daytime, algae take up the carbon dioxide that is free in the water. This decreases the carbon dioxide concentration to its lowest level in the afternoon time.

At this very point of time, the level of the dissolved oxygen is the maximum. Later during the night, the respiration of the aquatic animals produces carbon dioxide and its concentration is around 10-15 mg/L.

Co2 concentrations are the highest when the oxygen concentrations are the lowest. Moreover, some evidences suggest that the toxicity of carbon dioxide is enhanced when the concentration of the dissolved oxygen is low.

Fishes reduce the internal Co2 content with the help of the gills. This is in response to the difference of Co2 concentrations in the fish blood and the surrounding water.

If the fishes are unable to rid themselves of the internal carbon dioxide content, it shall accumulate in their blood. This may happen if the carbon dioxide content in the atmosphere is high.

The accumulation of Co2 will not allow the oxygen carrying molecules in the fish blood to bind with oxygen, and may cause suffocation to the fish.

Sometimes, the carbon dioxide present in the fish ponds may be a problem. When large quantities of organic material derived from dead plankton are decomposed, they increase the Co2 content and decrease the oxygen content. Co2 may also accumulate when fishes are held at high density.

Excessive Co2 can be removed by chemically treating the water with agents like quicklime or sodium carbonate. These agents react directly with carbon dioxide, causing reduced Co2 and increased alkalinity. These chemicals will, however, not remove Co2 completely from the pond water.

Also, treating the water with chemicals is a temporary solution. It may sometimes lead to serious consequences. The pH may increase in water sources with low alkalinity. The high pH causes a greater proportion of toxic ammonia in the water. This will further cause a stressful environment for the fishes.

For the management of Co2 in water, aeration and mixing are better solutions. Aeration increases the rate of diffusion of Co2 out of the water. Mixing will prevent the formation of the Co2 layer in the water.

To increase the uptake of fish Co2, moderate plankton density should be maintained. It should also be noted that a clear determination of Co2 in the fish pond should be made before any treatment is sorted.