Worm Factory Design Flaws
Sent by: Tim Schneider (Usa) on February 22, 2008 hour 15:29:22:
When we first started vermicomposting, I built the bin from my own design. It wasnít anything all that fancy, a two level flow-through system with a catch tray at the bottom, but its overall success was hampered by some unanticipated weakness in the design (beginning with a shoddy cutting job at Home Depot). We also overloaded the bin when we started, resulting in a cloud of fruit flies that did not clear until we moved the bin outside for the summer. I had a plan for a version 2.0, but when I finally priced the parts, I realized that I could purchase a well-reviewed commercial bin for less. I filed away my plans, and ordered a Worm Factory online.
The Worm Factory 16 in X 16 in sq.
Same basic design, but made of plastic that wouldnít rot or accumulate mold, a catch tray and spigot for drainage at the bottom, and stiff plastic grating between layers that wouldnít sag or come loose (see design weaknesses, supra). I unloaded the top tray from my old bin and transferred the compost into the stackable trays of the new bin, about four or five inches deep. I came back twenty four hours later to a monstrous scene: the worms squeezing out between the layers of the bin, red and writhing like hundreds of tiny tentacles. Unfortunately, I didnít take pictures.
The problem was that four layers of vermicompost, whatever the stage of decay, is very heavy and the Worm Factory is designed so that the trays stack inside oneanother. When fitted together snugly, or pressed tight (say, by the weight of successive stacked bins full of compost), this leaves 1.5 to 2 inches of space. The bible of vermicomposting, Worms Eat My Garbage, recommends a depth of 6 to 8 inches, which I found to be just right. Either way, I was pressing my worms to death. This is a pretty serious design flaw, and one I havenít found mentioned anywhere else online. It means that Iím only ever able to use a fraction of the binís capacity, since anything more than three stacked layers renders the bottom layer too compact for the worms to survive in and they migrate up and out. No composting gets done, and I end up with a half process and odiferous mess in the bottom layers. Not okay.
Whatís odd is that at least one of the pictures Iíve found online seems to anticipate this problem:
You can see here how the bin has plugs on the sides to keep the bins lifted off one another. These arenít present on mine. So Iíve got to figure out how to fix this, short of building my own bin from scratch again. Thoughts?
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