DIY (Do It Yourself) CO2 has been a growing trend among aquatic plant hobbyists who are trying to save a few bucks. There are many recipes out there, mostly containing sugar, yeast, and water, with maybe some baking soda. Some are better than others, but most of the time, hobbyists end up having to make new bottles every week or two.
Over a month ago, someone suggested to me that using a Jigglers(c) recipe of Jell-O(c) would last longer and be more consistent than the sugar and yeast concoctions. So, being time for a new bottle, I decided to try it. I had been using 3 cups of sugar and ½ tsp yeast in about 6 cups of water in my batches, which seemed to last a while. I really never noticed my plants bubbling though, which is the sign that they are getting enough CO2.
The recipe of Jell-O(c) I used contained 3 packets of Cherry Jell-O(c) (NOT the sugar-free kind) and two cups of water. This was really close to the Jigglers(c) recipe, which is 4 packets of Jell-O(c) to 2 ½ cups of water. The object was to get the Jell-O(c) tough enough that the yeast would have to take a while to get through it to the sugar.
I refrigerated the Jell-O as directed, and then when it was solidified, I added ½ cup of water and ½ tsp of yeast. I found the concoction took a week to start producing enough CO2 to send it through the airline into the tank. My airline is stuck into the bottom of my powerhead's prefilter sponge, and is churned through that into fine bubbles, which are spit out the spraybar located at the bottom of the tank.
The CO2 went way up to the 20 and 30ppm plus range. It was in that range for about 2-3 weeks. Then it went down slowly back to below 5ppm (which I consider not enough CO2 to be significant, and called it 0ppm).
I have never really tested my sugar and yeast CO2 batches, just went by eye and ear to realize they have stopped, so I can't really compare them. The only way I figure that the Jell-O(c) CO2 is better than the sugar and yeast, is that my plants actually had oxygen bubbles on them while using the Jell-O CO2. I made a chart of my readings, so maybe you can compare them with your sugar and yeast readings and see for yourself the difference.
I have started another bottle of the Jell-O CO2, and so far its been running great. CO2 is going up slowly, and there are already bubbles on my plants. There was so much CO2 bubbling out of it when I first attached it to my powerhead (a week after I made it -- I had it setting in my kitchen for that first week, knowing it wouldn't produce enough to even make it through the airline until then), that it stopped the powerhead a few times till it calmed down.
I will try to make a chart of my second bottle when it is finished and publish it also, so it can be compared to my first trial. In the second trial, I am using Red Raspberry Jell-O(c) instead of Cherry.