I have this guy here and have had problems mixing up the juice the last 2 times. First time: Was a few months back when I still had plants. I thought that I may have had a siphon go back into the CO[SUB]2[/SUB] reactor right away and spoil the mix. Just kind of blew it off for a while. Second time: Mixed it yesterday according to instructions. No siphon happened and no reaction either. It doesn't say to mix the ingredients after you are prompted to add the water and replace the lid. Seems like it should be mixed?