DIY CO2 does work, but it is a lot of routine work to keep it generating enough and steady enough CO2. If you use two or more bottles, with the start times staggered, so there is never a time when you have no CO2 at all, it works the best. Eventually we all get very tired of mixing sugar, water and yeast, and dumping what was in the water, but eventually stinks. If you can't afford pressurized CO2, the multiple bottle DIY CO2 is second best.I'm new in this. Will manual CO2 injection work, instead of CO2 system cos I can't afford a CO2 system at the moment.