I tried to make a "super-efficient" biogas generator, but it doesn't work

    My biogas generator is not working, even though it was only supposed to take nine days to ferment and it's been weeks.  It won't light.  I'm not getting any gas at all as far as I can tell.  It didn't get too cold, either.  The temperature inside my house has been 60-80 F the whole time.

    I built this biogas generator based on this video I saw on Youtube:

https://youtu.be/CmtAWQVZtl4

    It involves using a mixture of manure, plant waste, water, N-P-K fertilizer and rock salt to produce biogas much more efficiently than the mixture of manure/vegetable waste/water that many of us are familiar with.
    According to the video, the small 8-gallon tank of waste is supposed to generate enough gas to keep a flame lit for eight hours a day for one month.  Did anybody else try this/know about this method of creating biogas?

Not seen that one, but there is an Australian made digester that takes all sorts of scraps and creates enough gas to cook with.
I think I listed it here somewhere.
Home Bio-gas

I would check for leaks first, but seems you would smell if you had a leak.

Are you getting any of the indications it is starting to work, water in the bottle, anything like that?

John C Daley wrote:Not seen that one, but there is an Australian made digester that takes all sorts of scraps and creates enough gas to cook with.
I think I listed it here somewhere.
Home Bio-gas

Not australian, ISraeli...

Check out Solar Cities and Thomas H Culhane.

How to build a Solar Cities IBC biogas digester

Solar CITIES on facebook

Another source for bacteria culture is pond sediment. Your colony of bacteria may need time/an additional input?
Your reactor may not be warm enough? or consistently warm enough? add insulation?
Check for leaks, but might be difficult if not much gas is being produced... If you could test with compressed air, maybe one way?
Soapy water solution will show bubbles if there's a leak.

8 gallon digester means it is capable of generating 8 gallon of biogas per day when on the right temperature and fed with the right amount of food. It will never reach the maximum amount and quality possible.
1 m³ of biogas is about 3 hours of flammable gas. Your 8 gallons, which is about 36 liter, is far away from 1000 liter (1m³).  I would say you have gas for some minutes but not hours.