Add dry coir or shredded paper to reduce moisture in a worm bin.
Worm Bin Moisture
Perform the squeeze test to determine if your worm bin is too wet or too dry
The bedding in your worm bin should be as moist as a wrung-out sponge. To determine if your worm bin is too wet or too dry, try the squeeze test. To perform this test, take a small handful of bedding or processed compost in your hand and squeeze it tightly.
If you find that more than a couple of drops of moisture come out, your worm bin’s conditions are too wet. One sign that a bin is too wet is that it has offensive odors. This is caused because there is not enough airflow so anaerobic bacteria (the smelly kind) thrive instead of aerobic bacteria (the odorless kind). Feeding high-moisture foods such as fruits and tomatoes can cause a worm bin to become too moist.
To correct a wet bin, add dry shredded paper or coir, which will help to soak up excess moisture. You can also stop feeding high-moisture foods (fruits and tomatoes) until your vermicomposter becomes drier. We recommend keeping the spigot in the collection tray open at all times with a plastic container underneath to catch the leachate. This prevents flooding.
Although less common, worm bins can also become too dry. The Worm Factory 360 runs a little dry in contrast to sealed vermiculture systems because of its well-ventilated design.
In dry worm bin conditions, you can mist the top layer with a spray bottle.
To correct a dry bin, you should always keep a layer of moist full sheets of newspaper over the food and bedding in your top tray. If you find that your worm bin is not moist enough, you can add more high-moisture foods and re-wet the moist newspaper cover. You can mist the newspaper cover periodically with a spray bottle. In very dry conditions, very small amounts of water can be poured on top of the contents of the feeding tray and let it filter down to the lower trays. Be very careful while doing this, though – too much water can cause bedding to compact creating offensive odors.