DIY CO2 is a matter of taking Yeast and Sugar, and mixing them with water to create a reaction by product of CO2 gas. This works extremely well for 1-30 gallon tanks. For larger aquariums you must use more DIY bottles to increase CO2 output. It requires more effort, and most tend to go over to pressurized because the time and effort, and added cost over time required. But it can be done. Equipment: 1.
Gatorade, Apple Juice, or Oceanspray Bottle 2.
2 Cups of Sugar 3.
1/4-1 teaspoon of yeast 4.
1/4 teaspoon of baking soda (optional) 5.
Diffusor: Hagen Ladder, sweetwater AS10, or through filter intake Recipe: 1.
2 Cups of Sugar 2.
1/4-1 teaspoon of yeast (more yeast = faster reaction = more CO2 for shorter time (2+ weeks)) 3.
1/4 teaspoon of baking soda (optional) Making the Canister (Reaction Bottle): 1.
Take drill bit or hammer and a small nail (smaller than the diameter of tubing). 2.
Unscrew your cap, hammer/drill the nail into the cap to make a small hole 3.
Get some Airline tubing and pull it through the small hole with pliers. 4.
The small hole will create a seal around the tubing so no need for glue, hence the extra small hole. Adding the Recipe: 1.
Add 2 cups Sugar 2.
Fill the container with water up to 3/4 way. 3.
Add 1/4-1 teaspoon yeast 4.
Add 1/4 teaspoon (baking soda) 5.
Put the cap on and twist it on tight. Diffusion Methods 1.
Line directly into the intake of your filter, 2.
Limewood Diffuser 3. Sweetwater stone AS10 4. Hagen ladder 5. Glass difusser Wait a few hours and you got CO2 Special Notes: Check Valve Prevention System + Yeast Strainer
In order to keep the Yeast Muck from being released into your tank, A bubble counter or separator
is used to catch the muck. This DIY bubble counter also provides a check valve system to prevent water from back siphoning out of the aquarium.
from Rite Aid, Long Drugs, Walgreens, etc, can be paired with a standard plastic check valve to make this DIY bubble counter. 1.
Take the plunger off 2.
Add some glue to the check valve 3.
Insert check valve and dry for 24 hours. 4.
Once dry, the tubing will fit on the end of the check valve, and at the end of the syringe nozzle. 5.
Insert this between the diffuser and your reaction bottle. NOTE:
Some plastic check valves occasionally don't work, always check your valve when replacing the DIY CO2 mixture. CO2 will degrade plastic valves over time, so always check. For Larger Tanks
For larger tanks, and those that need to lower the ph more with more CO2 output. Using multiple diffusers placed at each side of the tank (left, right, middle, etc) will increase CO2 dissolution. In addition, you can add a T-valve to connect multiple bottles and to own diffuser to produce more out of your diffuser. Here
is an example. Placing the diffusers under a current will blow the CO2 around and further increase CO2 dissolution and contact time with the water. Is it working?
You should see bubbles coming out within 4-24 hours. To see if your CO2 is being properly dissolved based on whichever diffusing method you chose, test your Ph before adding CO2, and after adding. You will see a drop. Refer to a PH and KH chart
to see what your levels are at in ppm.
This reaction will last at least 2 weeks to 4 weeks. The more yeast added the faster the reaction but shorter duration. Be careful, and enjoy your CO2.