DIY Carbon Dioxide

Yeast Reactor

By Andrew Leaming aka Scitzfish - If you want a tank full of lush plants then a constant supply of CO₂ is a must. This can be done in two ways; spend hundreds of dollars on a commercial unit or make one for next to nothing, take your pick!

Materials

2 Litre plastic soft drink bottle
Suitable length of air tubing
Silicone glue
Sugar
Brewer's or Baker's Yeast
Water
Air Stone (Wood diffuser even better)

Construction

1. Drill a hole in the lid of the 2L soft drink bottle(same diameter as tubing)

2. Glue the end of the tubing into the bottle top making sure you have a good seal, as you don't want to lose that CO₂.

3. Attach air stone to the other end of the tubing

4. Add the follow mixture bottle

Yeast & Sugar mixture

Add a cup of sugar to the bottle
Then a teaspoon of yeast
Fill the bottle up with warm water(this activates the yeast) to the point at which the bottle begins to taper up

5. Shake the bottle to mix.

Placement & Maintenance

Place the air stone under the filter outlet so small bubbles of CO₂ are sent around the tank

This system lasts for around 10-12 days (depending on the temp.), and a second culture can be made on the 9th day to ensure a constant supply of CO₂. This method is ideal for some tanks around 80 - 100L

For larger systems use 2 or more DIY CO₂ reactors.

N.B. CO2 WILL LOWER YOUR PH SO BE CAREFUL!