I’m going to start experimenting with CO2 fertilisation for plants with this simple Dupla Co2 Omega Reactor, it’s just 200g of sugar and yeast, in a bottle with an airline tube into a tank. A DIY version can be made very easily with a pop bottle. I’ve dissolved the sugar in warm water from the kettle, I’m just waiting for the temperature to drop to 25 degrees C before and add the yeast, I don’t want to kill the yeast, if the water is too hot.