Micro-worms are the easiest live food to culture for feeding small fish and/or raising fry.

What are Micro-Worms?
Imagine an tiny earthworm, so small you can barely see them, and then only if you strain your eyes. The perfect food for tiny fish.

a microworm culture
An active microworm culture

The yeast I use

take me, take me
Worms crawling up the side
for easy harvesting.
Culturing Micro-Worms
You will need the following:
A small plastic container such as a clean margarine container, with lid
A starter culture of micro-woms
Food – any of these – oatmeal, cornmeal, pablum, baby cereal or even a piece of bread
Yeast – baking yeast or brewers yeast

First punch a few holes in the lid of your culturing container. You can use a nail or a knife to do this, be careful! Then add your cereal or bread, add water to make it to about the consistency of breakfast oatmeal. Sprinkle a little pinch of the yeast on top, and add the starter culture worms. You’re all set now.

Using Micro-Worms
Keep the worms at any reasonable room temperature. In about 3 or 4 days you’ll see millions of these tiny worms crawling up the sides of your container. You can then harvest them. Use your finger to just wipe a few thousand off the side and then swish your finger around in the tank to be fed. If your’e squimish you can use a knife or popsicle stick to scrape off the worms.You can harvest like this for days at a time.

If your culture seems to be slowing down, just sprinkle a little more yeast on top and/or add some more food and it should perk right up again. But sooner or later you’ll need to start a new culture. To do this just scrape off as many worms as you can and use them as a starter culture, and repeat the steps above. It is considered good practice to keep a reserve culture going in case your main culture dies out unexpectedly. You’ll need to look in on the worms every few days at least, because there is nothing in the world that stinks as bad as a ripe, dead micro-worm culture.

I f you need a lot of microworms in a very short time you can place the culture container on top of a heat source such as a flourescant light. The heat will make the worms produce faster and climb up the walls of the container much more than normal. If you do this be sure to have a back-up culture going because it really makes them age fast.


Mini-Microworms (also known as Walterworms) are a smaller version of regular Microworms. The only difference is the adult size of the worms. These are excellent for the super tiny fry like Gouramies, Bettas and Tetras.