Hey Worm People,
Did you know your worm bin is filled with dihydrogen monoxide?
Sounds scary. Don't rush to do any irrational tests.
Dihydrogen monoxide is water.
Water—it’s everywhere. We are 80% water, and so are our worms. Moisture control is a primary component in managing a healthy worm bin. Understanding how water interacts with your worm bin materials is vital to maintaining balance for a thriving herd.
Moisture: Key Terms
- Water Holding Capacity: The ability of your bedding to retain moisture, ensuring that the bin stays moist enough for worms without becoming waterlogged.
- Field Capacity: The maximum amount of moisture your bin can hold before excess water starts to drain, helping to prevent oversaturation.
- Porosity: The amount of space between particles in the bedding, which affects air circulation and water drainage, maintaining a healthy environment for your worms.
- Capillary Action: The movement of water through small pores in the bedding, helping to distribute moisture evenly throughout the bin.
- Hydrophilic vs. Hydrophobic Materials: Hydrophilic materials absorb water easily, while hydrophobic materials repel it. Choosing the right mix of these materials helps maintain proper moisture levels.
- Leachate: The liquid that drains out of the bin. Managing leachate effectively prevents harmful conditions caused by excess moisture.
This guide will help you better understand how to manage these factors for a safe and healthy herd.
If you are new to worm farming or repeatedly encountering the same problems, take our course Learn to Worm. Captain Matt will walk you through everything you need to know. It's informative and entertaining. It will give you the knowledge you need to be the best worm farmer you can be.
The importance of Moisture to our Worms
Worms breathe through their skin. Oxygen dissolves from the air into the layer of moisture on their bodies. If your bin is too dry, the bedding and food will draw this moisture out of the worms, inhibiting their ability to breathe. If your bin is too wet, it will prevent the oxygen from the air from reaching the worms and create an anaerobic environment.
Finding the Sweet Spot
The key to successful moisture control is finding that sweet spot where your bedding is as damp as a wrung-out sponge—moist but not dripping. If you grab a handful of bedding and give it a squeeze, you should get a drop or two of water, but not a stream. This balance ensures your worms stay hydrated and active without drowning or suffocating.
We want to maintain our moisture levels in our bin right below field capacity.
Common Moisture Issues
Let’s look at some common moisture problems you might encounter:
- Too Wet: If your bin feels like a swamp, it’s time to take action. Too much food waste, especially high-moisture scraps like fruits, can lead to excess water in the bin. Poor drainage can also be a culprit. You might notice a bad smell or see worms trying to escape. The fix? Add dry bedding with good water-holding capacity, like shredded newspaper, cardboard, or coconut coir, to soak up that extra moisture. Also, ensure your bin has proper drainage and isn’t sealed too tightly—worms need to breathe too!
- Too Dry: On the flip side, if your bedding feels like a desert, it’s time to add some moisture. Maybe you’ve been too cautious with watering, or the environment around the bin is too dry. If you see your worms looking sluggish or finding the bedding too coarse, lightly mist the top with water or add some damp bedding. Capillary action helps ensure that moisture is distributed evenly, so selecting bedding with the right pore size can help maintain consistent moisture levels.
Managing Moisture with the Right Bedding
Choosing the right bedding materials is important for moisture balance. See our bedding guide for more details about the right worm bin bedding.
- Coconut Coir: Highly hydrophilic, this material retains moisture well, making it ideal for dry environments. In humid environments, it can become waterlogged.
- Shredded Newspaper: Absorbs moisture quickly but can dry out fast. It’s perfect for wetter climates or bins that tend to get too moist. Its high porosity allows for good air circulation, but it can clump up if it's not mixed with other materials.
- Peat Moss: Holds moisture effectively and is excellent for maintaining consistent humidity levels. Be cautious, though, as it can become compacted if too wet, restricting airflow and affecting capillary action. It's also acidic and should be neutralized with lime or eggshells. Not being a renewable resource - it is best to use it along with other materials.
- Straw or Hay: These materials have high porosity, providing good drainage and air circulation. They don’t retain much moisture, so they may need more frequent watering, especially in drier conditions. These also break down slower.
- Shredded Cardboard: Shredded cardboard is a good material to buffer moisture levels. If your bin is too wet, add dry cardboard. If it's too dry, add wet cardboard. Adding wet cardboard instead of water helps prevent excess lechate. Always use dechlorinated water.
You get to experiment and find out what combination of bedding materials works best for you according to your climate. The fun part of worm farming is experimenting to create the perfect balance.
Monitoring and Adjusting Moisture Levels
What we measure, we can manage.
- The Squeeze Test: A simple and effective way to check moisture levels. Grab a handful of bedding, squeeze it, and see how much water comes out. If it’s just a drop or two, you’re in the sweet spot.
- Moisture Meters: For more precise monitoring, consider using a moisture meter. Go to your local nursery and pick up a simple moisture tester. Support your local shop. If they don't have one, we recommend this Moisture Meter on Amazon (Affiliate Link).
We receive a small commission if you purchase through our affiliate link at no additional cost. Thank you for your support. We recommend you check your local nursery or garden supply store first. Local is always better.
- Barometers: If you are still young, your joints haven't become barometers yet. You will need to purchase one. A barometer can help track humidity levels around your bin in regions with fluctuating weather. You can find great old-school barometers at thrift stores, but if you want an easy-to-read digital option, we recommend this one:
Dealing with Leachate
Leachate is the liquid that drains out of the bottom of your worm bin. While some leachate is normal, excessive amounts can indicate overwatering or poor moisture retention. To manage leachate effectively:
- Make drainage holes in your bin to maintain good porosity and prevent waterlogging.
- Consider using a collection tray to monitor how much leachate is being produced.
- If you notice too much leachate, reduce watering and add more dry bedding to absorb excess moisture.
- If you use a tray system, you can place a few trays of bedding under your feeder tray. This will catch the excess moisture and inoculate the bedding for the future.
- Very fresh leachate is fine to use in the garden... but it can quickly go bad - so most folks get rid of it to reduce risks.
Controlling Moisture During Different Seasons
Moisture levels can change with the seasons:
- In Dry Seasons: You might need to add more water or include more hydrophilic materials like coconut coir to retain moisture and maintain the proper water-holding capacity.
- In Humid Seasons: Focus on improving drainage and airflow to prevent over-saturation. You might also need to add more porous, hydrophobic materials like straw to balance the moisture.
Troubleshooting Moisture Problems
If you’re still struggling with moisture issues, here are some additional tips:
- Experiment with Bedding Mixes: Don’t be afraid to try different combinations of bedding materials to find what works best in your climate.
Learn more about the different types of bedding and their advantages and disadvantages in our Worm Bin Bedding Guide.
- Adjust Feeding Practices: Avoid overloading your bin with water-heavy foods. Balance out wet foods with dry bedding to keep moisture levels in check.
Learn more about worm food and download Captain Matt's worm chow recipe card from our Worm Food Guide.
- Location, Location, Location: Consider where your bin is placed. A garage might be too humid, while a shaded outdoor area might provide better ventilation.
Moisture Management Insights from the Worm People Community
We asked, and you delivered. Thank you to everyone who provided insights. The Worm People Community is the best place on the internet (maybe we are slightly biased).
1. Dealing with Dry Conditions:
- Louis Schrader from Alaska mentions that the air can get extremely dry during the winter, with humidity levels dropping to 30%. To combat this, he uses an organic wetting agent and mists his bins every 3-4 days to maintain adequate moisture. This helps ensure that the bedding stays moist even in a dry environment.
- What’s a Wetting Agent? As George G explains, a wetting agent reduces water's surface tension, making it easier for water to soak into the bedding rather than bead up and run off. This is especially useful in dry conditions or with hydrophobic materials.
2. Managing Moisture in Warm Climates:
- John Bush from South Texas uses mortar trays and a pump sprayer to moisten his bins. He feeds his worms every two days and adjusts the moisture based on the presence of pests like roaches, which indicate dryness. He also fluffs the bedding regularly to prevent compaction, ensuring proper air circulation and moisture distribution.
- Observation: John notes that while he generally avoids standing water, worms don’t mind a little bit of it as long as the bedding isn’t overly saturated.
For more information about managing your worm bin during the hot summer months, check out Beating the Heat.
3. Different Zones for Different Moisture Levels:
- Jennifer from Restoring Roots in Tennessee has observed that her worms tend to congregate in the wettest parts of the bin. She adjusted her approach to keep one side of the bin extra wet while maintaining the other at a more traditional moisture level. This allows the worms to move between different moisture zones depending on their preference.
4. Using Dry Bedding to Manage Excess Moisture:
- Lesli Sagan and Jim Butterfield place dry bedding trays underneath their feeding beds to absorb excess moisture. This helps manage the active tray's moisture levels and preps the lower trays with inoculated bedding for future use.
5. Keeping Moisture Levels Consistent:
- Louis Schrader also adds that he follows the general rule of maintaining 70-80% moisture when temperatures are between 70-80°F. While worms can tolerate up to 90% moisture in warmer conditions, keeping within the 70-80% range is ideal for most situations.
Thanks again to everyone who participated and shared their experiences. Join the conversation here.
Wringing it out
Maintaining the proper moisture balance in our bin is very important. Use this guide to help you better understand what is going on and what steps you should take to manage it. When your worm bin is at the perfect moisture, the oxygen and pH tend to stay in balance, and your worms make the most cocoons and castings.
Happy worming!
