Check this out for basically free live food for your fry...
Vinegar eels are a great source of food for small fry and can also be used as food for really small adult fish. Since Vinegar eels are so easy to cultivate at home, you can always have a culture going in case your fish decides to spawn. Feeding fry live food instead of powdered flake food or similar increases the survival rate for most species and will also aid rapid growth and development. Live food is less likely to foul the water, since live creatures will stay alive until consumed instead of starting to decompose. During periods that you have no fry to feed, your adult food will most likely gulp down any excess vinegar eels, especially if you keep fairly small fish species.
* Get a glass container to raise the vinegar eels in, e.g. an empty food container. The container should have a tight fitting lid to avoid insects from entering the culture.
* You need to obtain a vinegar eel starter culture from a fish store or your local fish club.
* Vinegar eels are called vinegar eels since they can be raised in vinegar. Mix one part apple cider vinegar with one part aged tap water. (If the tap water in your area is really hard, use 40% aged tap water and 60% apple cider vinegar.) Avoid using vinegar that has been distilled. If you want to, you can also add a small piece of apple to provide extra nourishment.
* Add the vinegar eel culture and place the container at room temperature, out of direct sunlight. After 2-3 weeks there will be enough vinegar eels in the container to start harvesting them.
* Pour 2/3 of the vinegar-water with the eels through a coffee filter into an empty jar. The adult vinegar eels will be trapped by the coffee filter and can be poured into another jar filled with aged water, before being fed to your fry. The water that was poured through the coffee filter still contains juvenile vinegar eels that should be returned to the old culture. (Don’t forget to add more water and vinegar to the old culture if necessary.) You can also use them to start up new culture in other jars.