Another DIY c02 recipe
There are a few of them out there, but this one has never failed me. Measurements are for a three liter soda bottle if you have a two or smaller obviously you will have to adjust the measurements.
5 3oz packets of jello(cheapest you can find)
2.5 cups sugar (cheaper in stores with bulk bins/scoop yourself)
3/4 cup whole wheat flour (nutrients for the yeast, cheaper if you can find it in stores that have bulk bins)
1/8 teaspoon of champaign yeast (sometimes hard to find, try to find a brewing supply store or a natural food/Co-op store in your area)
1/4 teaspoon of baking soda (again bulk bins)
7 cups of water
Heat 3.5 cups of water. When comes to a boil take the pot off the burner and mix in jello until dissolved then sugar until dissolved. Next mix in 3.5 cups of cold water then the wheat flour. Pour the jello in a pan (13x9 or whatever you have) and place it in the fridge to set. Once set cut the jello into cubes that will fit through the opening of the soda bottle (cubes will create more surface area for the yeast. Next activate the yeast in a cup of tepid water for about 15 minutes. Then pour yeast water in the bottle. Add baking soda and if need be fill the bottle with more tepid water until it reaches the part of the bottle that curves. Then hook the bottle up to your system.
One key part to my system is that my bottles of fermenting jello are always keep at 70 degrees. Somewhere I read on some brewing sites that temp was optimum for yeast. I live in a cool climate so my bottle is in a bucket with water and a heater. I actually have a two bottle system but only one going at a time. The only time both are hooked up is when one is almost done and I am starting another (It takes about a day to get it going).
This system is on a tank in a non profit animal rescues adoption room. Its a 46 gallon tank with 96 watts of light. I change the bottle out once a month but do a quick visual check once a week while doing a water change. Plants are happy. I have been using this recipe for a year now and while it does take a little bit more work I have never had a problem with it. Hopefully this will help someone. Take care.