a good question, and one i have wondered myself. Like you i have made a few differant configurations, 1/2 tsp, 1/2 pack, 2 cups sugar, 6 tblspn grape jelly, Bakers yeast, Brewers yeast, etc etc, all or course in a 2 litre bottle and paired 2 litre bottles.
best results so far is a single 2 litre bottle, lukewarm tap water, 2 cups sugar, 1/2 tsp bakers yeast. lasted approx 3 weeks.
raised my CO2 in my 55 gal to just over 9%. Very good plant growth resulted.
Two bottles did not increase the time it lasted only increased the amount output.
Next trial is 1 gal with same sugar / water concentration, but volume increased to match 1 gal. and yeast stays the same as 2 litre bottle.
Should yeild same output, just go longer. I Hope. Someone else want to jump in here and take a wack at the One Gallon? or has tried a one gallon with lower Yeast?
best results so far is a single 2 litre bottle, lukewarm tap water, 2 cups sugar, 1/2 tsp bakers yeast. lasted approx 3 weeks.
raised my CO2 in my 55 gal to just over 9%. Very good plant growth resulted.
Two bottles did not increase the time it lasted only increased the amount output.
Next trial is 1 gal with same sugar / water concentration, but volume increased to match 1 gal. and yeast stays the same as 2 litre bottle.
Should yeild same output, just go longer. I Hope. Someone else want to jump in here and take a wack at the One Gallon? or has tried a one gallon with lower Yeast?