Constructing a CO2 Reactor

Fig. 1 [(+/-)] CO2 reactors are used to deliver bubbles of carbon dioxide (carbonic acid) to plants growing inside an aquarium.


Fig. 2 [(+/-)] Plants thriving inside fully aquatic environment.

Fig. 3 [(+/-)] Pressure built up inside the CO₂ Reactor pushes the gas through the small plastic tube and into the tank for circulation. A small air stone is attached at the end of the tube (see figure 13). For information on airstones, go here, Air Stones for Aquariums.

"Air stones provide very fine air bubbles, much finer than those released from a piece of tubing attached to a pump. For the aquarium keeper this means more oxygen in the water. Oxygen absorption is improved by the large surface area of the smaller bubbles. Adequate oxygen can increase the amount of fish that your aquarium can hold." (e-aquarium.com.au)

A CO₂ Reactor of this nature should begin working within 1-2 days, and should last approximately two weeks. The process to construct a CO₂ Reactor involves a few simple steps and ingredients:

·Water
·Sugar
·Yeast
·Baking Soda

CO₂ for plants lowers the PH level in water, and improves water quality for fish.

Fig. 4 [(+/-)] Bottle which has been thoroughly cleansed of all liquids and fitted with plastic funnel.

Fig. 5 [(+/-)] Granulated sugar is added.

Fig. 6 [(+/-)] Measurements are approximate.

Fig. 7 [(+/-)] Yeast is an important ingredient in the creation of a CO2 Reactor.

"Yeasts are unicellular eukaryotic microorganisms classified in the kingdom Fungi. Approximately 1,500 species of yeasts have been described,[1] most of which reproduce by budding, although in a few cases by binary fission. Yeasts measure about 3µm varying across species. The yeast species Saccharomyces cerevisiae has been used in baking and fermenting alcoholic beverages for thousands of years. It is also extremely important as a model organism in modern cell biology research, and is the most thoroughly researched eukaryotic microorganism, which gathers information into the biology of the eukaryotic cell and ultimately human biology." (Wikipedia)

Fig. 8 [(+/-)] Yeast added to the mixture.

Fig. 9 [(+/-)] A clump of Sodium bicarbonate, Baking Soda is added.

Fig. 10 [(+/-)] Warm water is added until bottle is approximately 3/4 full.

Fig. 11 [(+/-)] All ingredients have been added and the bottle should be capped and firmly shaken.

Fig. 12 [(+/-)] Shaking the mixture helps sugar dissolve in the warm water. Yeast breaks down the sugar, converting it to carbon gas

...yeast causing fermentation can be detected by observation. The first indication of ferment is the appearance of tiny bubbles, which collect on the sides and the bottom of the vessel and then gradually rise to the top. These bubbles are a form of gas called carbon-dioxide, or carbonic-acid, gas. Gas, acid, and alcohol are three results of the action of the ferment. (Basics about Ferment)

Fig. 13 [(+/-)] A small hole should be drilled through the cap, to fit the line of plastic tubing. Care should be taken to ensure this hole is no larger than the tubing or gas will leak around the line instead of being pumped through into the aquarium. Securely tighten the cap on the bottle. The bottle will be under significant pressure as chemical reactions occur over the following two weeks.
An airstone is placed on the opposing end of tubing, inside the aquarium.

Related Links to Carbonic Acid in Water
CO₂ and Water Hardness
Carbonic Acid, Wikipedia
What happens when water mixes with carbon dioxide.
H2O + CO2 ->H2CO3 (carbonic acid). Hydrogen bonds to carbon instead of oxygen.
Making Carbonic Acid
Carbon Dioxide and Carbonic Acid, Chemistry Page
Chemistry and Aquaria
A series of solutions to common pH problems.
Airstones, how to clean and rejuvenate old airstones.