Your website is absolutely amazing, the best I have come across!! According to your two-stage design and corresponding literature you suggest that the acidogenesis stage and methanogenesis stage have a HRT of 3 days to 9-10 days respectively. After 3 days in the acidogenesis compartment, is the sludge then transferred to the methanogenesis compartment? And is this methanogenesis compartment initially empty? Is the sludge transferred from the acidogenesis tank to the methanogenesis tank via displacement following feeding the reactor after 3 days? I guess I am a little unclear of the flow and timing of organic/animal waste to the acidogenesis tank to the methanogenesis tank. My understanding is that pH is vital to the existence of each microbial stage. How or what would you recommend to control for the pH in each stage and suggest for "seeding" the reactor?