Indoor Compost Tubs

Indoor compost tub

What are indoor compost tubs?

Compost tubs are essentially just an indoor compost bin. Moderate amounts of food waste are layered with shredded paper and dry soil. This method is effective but requires close monitoring to keep from making a mess.

What composting style do they fit?

Compost tubs require close management and a solid understanding of how to balance compost ingredients, so they should only be attempted by experienced, hands-on composters. 

What space do they need?

Compost tubs need an indoor space.

Can you use them all year?

Compost tubs are an indoor system and can be used all year.

How do they work?

Indoor compost tubs rely on natural decomposition microbes like fungus and bacteria to consume organic matter and transform it into humus, the organic component of healthy soil. While compost tubs follow the same 5-step recipe as outdoor compost bins, using them indoors means it extra imperative to keep them into perfect balance so that they do not smell. For review of the basic recipe (nitrogen, carbon, water, air, and soil for microbes), check our link on compost bins.

Assembly instructions:

  • Drill holes in the sides and bottom of a large tub. Set the tub on top of a drip tray, preferably on up on bricks or other spaces so air can circulate. Drill holes in the lid.
  • Add a 1-2" layer of dry soil or finished compost to the bottom of the tub. Because this method is indoors, this soil/compost will be the main source of decomposition microbes. Potting mix does not work for this and should not be used as a substitute.
  • Add a 1-2" layer of dry shredded paper or sawdust to the tub.
  • Begin adding plant-based food waste and eggshells to the tub. Balance each addition of food waste with a slightly larger amount of shredded paper or sawdust. Add a thin layer of soil every several inches.
  • Carefully fluff or stir the contents of the tub every week. If the contents are quite dry, add water a cup at a time. Try not to overfill the tub.
  • Over 2-4 months, the contents of the bin should look more and more like crumbly soil, with some bits of fresh food waste mixed in. When the contents also smell earthy - rather than sour or rotten - the compost is ready to use.
  • You can top up potted plants with the compost or take it to an outdoor garden.

 

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Got more composting questions? Email the Compost Hotline at [email protected].