HRT - hydraulic retention time is period taken for a waste to be digested to produce biogas completely at particular temperature

I am very lucky able to find old air temperature data at my place. The average is like 26.8 celcius. So, according to David David William House 's graph, the approximate HRT is 45 days. So, it is safer for me to decide to choose 50 days HRT for my digester. To determine how much to feed daily is by calculating = digester volume (liter) / HRT (day) = 200 liter/50 days = 4 liter/day. Again, rule of thumb do not get solid food waste over 50% of daily feeding volume. In my case for 4 liter feeding, 2 kg of food waste is the maximum volume then mix with 2 liter of water to a total of 4 liter. If you do not have confident and do not want to get your system sour lets try less than 50% food waste of your daily feeding volume. Please try and error, experiment with your system and you will learn a lot finding the most optimum condition to run your system. Want to construct your own biogas biodigester? Click here!