Culturing Microworms and Banana Worms | Nutritious Fry Food Made Simple

Microworms and Banana worms are beloved by aquarists for good reason, they are easy to culture, packed with nutrition, and perfect for feeding tiny fry. These soft bodied nematodes (worms!) wriggle enticingly at the water’s surface, making them ideal for species that feed mid to top level. Whether you're raising pea puffers, danios, rasboras, pseudomugils, bettas, or dwarf cichlids, this guide will walk you through setting up and maintaining a thriving culture with minimal fuss.

What You’ll Need:

• Plastic or glass container with a lid (e.g., food tub or jar)
• Instant or quick oats (the cheaper the better, with nothing added)
• Active dry yeast
• Water
• Microworm or banana worm starter culture

Prepare the Culture Container

Start with a clean slate:

• Wash your container thoroughly with hot water and dry completely.
• Poke small holes in the lid or cover with a breathable material (like a paper towel secured with a rubber band). This allows airflow while keeping contaminants like ants, flies and other creepy crawlies out.

Mix the Culture Medium

1. Cook the oats: In a separate bowl, mix instant oats with water and cook until thick, like porridge.
2. Cool completely: Let the mixture cool in the fridge, ideally overnight.
3. Add yeast: Sprinkle a small amount of active dry yeast over the cooled oats. This helps ferment the mixture and feeds the worms.
4. Stir well: Mix thoroughly to distribute the yeast.
5. Transfer: Pour the oat mixture into your clean container, just enough to coat the bottom.
6. Add the Worm Culture: Sprinkle your microworm or banana worm starter evenly across the surface of the oat mixture. No need to mix, just let them settle in.

Incubation

Place the container in a warm, dimly lit spot. Ideal temperature range: 20°C to 28°C

Let the culture sit undisturbed for a few days. You’ll soon notice a wriggling layer of worms crawling up the sides of the container, they are now ready to harvest!

Harvesting

After 3-7 days, your culture should be teeming with worms.

To harvest:

• Use a clean brush, spatula, or even your finger to gently scrape the sides of the container.
• Transfer the worms into a small container.
• Mix with dechlorinated water to help distribute them evenly in your aquarium.
• Use a pipette or dropper to feed fry and small fish directly.

Splitting & Refreshing Your Culture

As your microworm or banana worm culture grows, it’s a good idea to expand or refresh it to keep things thriving:

• To split or restart: Scoop a portion of the active worm/oat mixture into a fresh container with newly prepared oats and a sprinkle of yeast.
• Why it helps: Having multiple cultures going at once gives you a safety net in case one crashes or dries out.
• When to refresh: If the culture starts to smell sour, dry out, or slowdown in production, start fresh using a healthy portion from your best performing batch.

With regular harvesting and occasional refreshing, a single culture can last several weeks to months.

Microworms and banana worms are a fantastic, low cost way to support healthy fry growth, especially in the early stages when nutrition and accessibility matter most.