Thinner reactor more efficient: more light = less power used to circulate water in a larger volume container.

Best?:
http://www.youtube.com/watch?v=OebPtG6J-dg&feature=related
- Two sheets of 5 mil plastic, apply heat to weld together. Weld up the sides. Weld in a zig zag pattern as shown in vid to allow water to fall from chamber to chamber. Thicker plastic easier to weld and stronger, but less light passthrough.
- Need controlled heat source: Weller solder iron? If so, need new (fatter) tip as will be useless for soldering after melting plastic. Heat gun and metal strip clamps for outside?


Hmm:
http://www.youtube.com/watch?v=bsQCj_PaWN0
- recycles bottles, but more energy intensive, no gravity assist.
- easier to make, no plastic sheet welding involved.

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Resources:
- Waste water.
- Electric pump (solar + battery source?)
- Vertical support rack (pergola in back yard? sides of house? fence?)


Processing:
- Empty reactor direct to oil press
- barrels for waste water (pump to garden/crops?)
- plastic bottles for oil catch/skim and filter

Would also need to build a biodiesel conversion rig if taking last step, though probably just mix oil in with higher quality purchased fuel to extend it. Means of production for stand alone fuel necessary in SHTF scenario though..