Microworms (*Panagrellus redivivus*) are among the simplest live food cultures to maintain. These tiny nematodes are the perfect first food for fry of tetras, barbs, and other species where newly hatched brine shrimp are still too large. They thrive on a substrate of fermenting oatmeal and multiply by the millions.
Establishing the Culture
To start your culture, use a shallow plastic container with a tight-fitting lid. Poke tiny air holes in the lid with a needle to allow gas exchange without drying out the media. 1. Prepare a base of oats moistened with water until it reaches a thick porridge consistency (approx. 2-3 cm deep). 2. Add a pinch of dry yeast to kickstart the fermentation. 3. Add your starter inoculum on top of the mixture. Keep the container in a warm, dark place to encourage rapid reproduction.
Harvesting and Feeding
As the culture peaks, thousands of worms will climb the sides of the container. You can easily harvest them using a finger, a small brush, or a cotton swab and dip them directly into the fry tank. A major benefit of microworms is their ability to survive in aquarium water for up to 24 hours, meaning they won't immediately foul the water if you happen to overfeed slightly.
Maintenance and Odor
Due to the fermentation process, the culture will naturally have a sour smell. To keep production high, add a tiny amount of fresh yeast weekly. After 2-3 weeks, the medium often becomes too liquid, and yields will drop. At this point, start a fresh culture by using a small scoop of the old one as an inoculum. It is always wise to keep at least two cultures running at different stages to ensure a constant food supply.
