Introduction: How to Culture Live Microworms for Fry and Small Fish

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Microworms are the perfect size newly-hatched fry, and are meant to feed fish that are too small to accept the traditional food such as pellet and flakes. This live food will move in the water which triggers the eating reflex of the baby fish. Microworms are essential a great start to a fry's healthy diet.

They can be used to feed betta fry, guppy fry, platy fry, corydora fry, killifish fry, larval newts, small tadpoles and more!

It's important to plant when to start your culture, so that by the time your fry have hatched, there will already be a large quantity of microworms that will suffice the needs of your fry.

Step 1: Materials Needed

Materials Needed

  • Microworm culture
    • You'll need to obtain a few live adult microworms to start your culture.
  • Plastic container (with a lid)
    • Will be used to house the culture.
    • A least 5" x 5" in size (12.7 x 12.7 cm).

    • Make sure to poke some small holes on the lid to let air in - to keep the culture alive.

  • Oatmeal
    • This will be used as the breeding media for the microworms
  • Active dry yeast
    • Main source of food for the microworms, only a small amount is initially needed.
  • Q-tips
    • To scoop up the microworms.
  • Pipette/dropper
    • To suck up the microworm and feed fry.
  • Small cup

Step 2: Setting Up the Microworm Culture

  1. To start out your microworm culture, get a clean container and add a 1 inch layer of cooked oatmeal to the bottom of the container.
  2. Let the oatmeal cool out overnight in room temperature, then mix in 1 tsp of the active dry yeast.
  3. Add the microworm culture to the cooked oatmeal - this will have a slightly fermented smell which is completely normal. Slowly mix the culture into the oatmeal.
  4. As the oatmeal ages, the microworms will feed off of the produced yeast. Put a lid on the container, make sure to poke some holes on the lid to let air in - otherwise the culture will die.
  5. Keep the culture at room temperature 68 - 85 degrees Fahrenheit (20 - 29 degrees Celsius), and away from direct sunlight and under vents.
  6. Stir the culture once a week to keep it alive.

Step 3: Feeding Microworms to Fry

  1. The microworms will climb up the sides of the container, using your Q-tips, swab a small amount of microworms.
  2. Swirl the Q-tip into a small cup of chlorine-free water. This method will prevent the oatmeal solution from entering your fry's aquarium water.
  3. Using the pipette/dropper, suck up the microworms that will lay at the bottom of the cup, and spot feed your fry. Feed them at a location in the tank where they will easily see and have access to the microworms.
  4. Microworms last 2-3 days in freshwwater. Remove any microworms after this period.

Step 4: Microworm Culture Maintenance

  • Using a plastic spoon or anything similar, mix the culture once a week. As microworms do not naturally burrow into the oatmeal (they just sit at the top), they need to be mixed weekly to keep the culture fresh.
  • Once a month, restart the culture. Get a small amount of the old culture, and use it to start a new one - otherwise the culture will go bad, you'll notice as the odor gets stronger.
  • It's good to have 2 cultures running at the same time, just it case one goes bad, you'll have a backup culture.
  • If you have a large amount of fry, it's best to start one new culture every week as the first ones are coming to the end of their productivity, you'll have another one that is ready to substitute it.