Compost worms eat half their weight in food every day. It is also important to always have food available for them but never to over-feed them.
One technique is to only place food when their supply is almost gone. This avoids rotting which would attract pests, warms-up the bin and may turn the substrate more acidic.
What can I feed them with?
Sweet fruits like banana peels, mangoes’ peels and papaya
Cardboard and paper
What not to feed them with:
Citrus and acidic fruits
Meats and dairy
Any alliums or vegetables with strong flavor
Avoid exposure to the sun and heat. Worms need a temperature of around 86°F max in the tropics.
Oxygen is essential so creating air-pockets in their bedding is vital. This can be done by adding shredded paper to the bedding.
Correct moisture is essential- A method is to squeeze a bit of the bedding in your hand. It should release a few drops of water but not more than that. You can add a bit of water if dry or add shredded paper if too wet.
Any liquid from the tub should fall in the bucket and be used as fertilizer. It can be used as-is to water the plants or mixed with water or as part of compost tea.
My favorite technique to harvest castings or worms is to feed the worms in only one side of the bin with ripe mangoes or a very sweet fruit for a week or more. Then, when most worms are on one side, you can either grab handfuls from the worm side or the casting side depending on what you are harvesting. By placing these handfuls in a bright spot will help separate any worms from any remaining bedding since they will dive down to avoid the light.
Replace any portions of bedding you took with fresh bedding.
What went well:
The population growth was immense and I had to add new bins quite quickly. The shade in the area helped significantly in keeping the bin at an appropriate temperature.
The drain bucket filled every few days and had to keep an eye on it so it wouldn't overflow.
The coffee tree next to the bin went crazy and turned red with fruit more frequently than before. Soil nutrition was increased as we saw in the gardens where the castings or worm juice was used.
What I would have done differently:
I should have designed the system with a lid so rain water could be diverted. Rain water provoked the system to be overflowed a few times while I was working overseas and many worms disappeared from the bin.
I should have also made a higher base so a 5 gallon could fit underneath.
Areas in front and near the worm farm where vermi-compost and worm juice fell, were getting a significant amount of weeds compared to other areas. A concrete floor was extended (see photo below) and the areas around the system were layered and deep mulched to minimize maintenance and to make it more aesthetically pleasing.
I plan to start sprinkling Rock Dust (Azomite) in 2021 so the worms make the dust plant soluble making the worm casting even more nutritious for our gardens and food forest.