Beginner Must Know - Carbon Dioxide (CO2)

Carbon Dioxide

CO2 Requirement For Aquarium Plants

Aquarium plants fix dissolved carbon dioxide (CO2) into carbohydrates through photosynthesis. This energy is stored in the stems leaves and tubers, fueling growth as required. It is only consumed during photoperiods when light is available.

Carbon dioxide levels can be supplemented to improve plant growth rates. This can be done by direct injection of carbon dioxide bubbles from an aquarium CO2 product or more primitively using a yeast reactor. Liquid CO2 might also be available in the form of carbonic acid.

There are a number of methods of helping the carbon dioxide bubbles diffuse into your tank water. The injection line can be fed into the impellor or Venturi intake of an internal filter. Alternately a diffusion bell or other product can be used to “catch” the bubbles and hold them until they dissolve.

Whatever method you use it is important to monitor the carbon levels. Large pH fluctuations can result if dissolved carbon dioxide is not kept level. This is generally a much bigger threat to fish than CO2 poisoning.

Surface water movement, splashing and bubbles should be kept to a minimum to keep the carbon dioxide from returning to its gaseous state and leaving the aquarium. For this reason submerged internal power filters are popular in planted aquarium.