I've only been doing CO2 (DIY) for a week now, but the recipes didn't work for me from that website. I think it was due to me not activating the yeast before hand. Also, I think you're supposed to fill the bottle up with more water to the bend. The one that I found that worked is this:
1/2 tsp yeast
1/4 c tepid water (104 F)
2 cups sugar + a pinch
you activate the yeast in a little cup by adding it to the tepid water and stirring vigorously with a fork. Once it's dissolved, add a pinch of sugar and stir it again. Let it sit until it's all bubbly and smells like bread. Fill the 2 liter bottle with 4 inches of hot water and add the 2 cups sugar. Cap the bottle and shake it really well. Add cool water to the neck (first bend) and add your activated yeast. Gently shake it to mix and hook it up to your tank. I have 2 bottles and I plan on staggering them. I made the 1 bottle last Sunday and tomorrow I'll do the other bottle and then every week I'll make 1 of them fresh. I think the mixes are supposed to last around 14 days. I just don't want a huge ph swing if I do both of them at the same time, so that's why I'm staggering them. So far I'm getting loads of CO2 in my tank. I think I'm at about 14 ppm.
