How to Make a Worm Farm Using a Bath

Making a worm farm using a salvaged bathtub represents a triple play for the environment: You remove the tub from the waste stream, add to it food scraps that would otherwise rot in a landfill, and harvest odorless, mineral-rich compost worm manure that creates strong, healthy plants. Plans for bathtub worm farms can be the epitome of simplicity.

Things You'll Need

  • Salvaged bathtub
  • Railroad ties or cinderblocks
  • PVC tub drain
  • Bucket
  • Lattice panel
  • Hardware cloth
  • Sheet goods for lid
Show More

Instructions

  1. Assembly

    • 1

      Shop for a salvaged bathtub. You'll likely find cast-iron bathtubs on Craigslist.org and Freecycle.org for free, and for about $30 and up (2009 prices) at junkyards and nonprofits that salvage and reuse building materials. Search on "Junk Dealers" and "Salvage and Surplus Merchandise" at magicyellow.com for potential local sources. Check also for free or low-cost acrylic bathtubs, which may weigh just 60 to 150 lbs. and will be easier for you to handle than cast-iron tubs, at 350 to 500 lbs.

    • 2

      Salvage or buy railroad ties or cinderblocks to raise your bathtub off the ground. Place three tiers of either ties or blocks under the lip of the bathtub, sufficient to place a drainage bucket below.

    • 3

      Install a PVC drain on the existing tub hole. Place a small bucket underneath to capture leachate from your composting process to dilute and place on your garden.

    • 4

      Cut salvaged lattice panel to the outline of tub such that it can rest inside the tub approximately 2 inches above the bottom, held up by either the convex curve of the tub itself or scrap wood pieces. Cover lattice with hardware cloth.

    Preparation for Worms

    • 5

      Fill the tub to within about 4 inches of the top with soaked, torn strips of cardboard or newspaper, mixed with dry, partly composted leaves or leaf mold, composted manure or a mix of other appropriate bedding materials. Add a handful of grit and crushed eggshells if available. (See Resources.)

    • 6

      Add 1 to 2 cups of kitchen scraps, coarsely chopped, nestled about 3 inches below the bedding surface.

    • 7

      Add red wiggler worms from an indoor worm bin, from a manure pile or via online order or telephone order from a nearby vendor. Visit Findworms.com to find commercial worm farms that ship red wigglers to home growers.

    • 8

      Cut a lid about 6 inches longer than the bathtub on all sides to keep the worms in darkness and to shed rain. Use salvaged exterior-grade plywood or a sheet of plastic. Place on top of the tub.