I picked up some components for my methane digester project this weekend. I picked up a 275 gallon tote tank similar to this one for $50 (normally these run about $175 in my area, but this one is missing the cap on top, which I would not be using anyway:
I also got a ~30 gallon holding tank and submersible sump pump for $50 that will propbably eventualy be a primary stage to the big tank’s secondary. The pump works great, and fills a 5 gallon bucket in literally about 3 seconds.
A buddy is taking out a pond at his house that was half-arsed built by a previous home owner, so I got some 2" and 4" ABS drain pipe and some valves out of that for free.
More to follow as I build the project, I will try to document with costs, steps, and pics as well as I can.