DIY: CO2 Generator for an Aquarium
- 1). Drill a small hole into the bottle's cap, making sure the opening is just large enough to fit the airline tubing snugly through.
- 2). Cut the airline tubing to the length you will need; make sure there is enough tubing to go from wherever the CO2 bottle will be housed, to the inside of the tank, with a little extra tubing for "wiggle room."
- 3). Insert one end of the airline tubing into the bottle cap from the top, allowing approximately 1/4 to 1/2 inch to protrude into the inside of the cap.
- 4). Apply a bead of aquarium silicone around the tubing on both sides of the cap, and set aside to dry for at least 24 hours.
- 5). Fill the 2-liter bottle with 2 cups of sugar, and add the yeast. Fill the rest of the bottle to within 3 inches of the top with lukewarm (not hot) water. Cover the bottle opening with your hand or a spare cap, and shake vigorously to mix.
- 6). Screw the cap with the tubing firmly onto the bottle, and connect the free end of the tube to the intake of your power filter or powerhead. Alternately, you can purchase CO2 diffusers or an air stone to act as bubble diffusers within the tank.
- 7). Replace the CO2 sugar/yeast solution every three weeks.
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