Infusorians is a suitable food for very small fish fry(Betta, or rainbows). You can easily grow your own Infusoria cultures at home. This way you will always have cheap and nutritious food ready for your fry. Infusorians are minute single cell organisms that live in water. To cultivate your own Infusoria you will only need tap water, some bruised vegetables and a few clean containers such as jars or similar.
Boil the tap water and let it cool down to room temperature. Fill the jars with the water and add some bruised vegetables to each jar. Bruised lettuce leaves or banana skins are recommended, since they are known to produce a lot of Infusoria. One banana skin or 3-4 lettuce leaves is a good amount for each jar. Do not put any lids on the jars. Place your jars in a warm place where they will receive moderate light.
The water in the jars will soon turn cloudy and begin to smell a bit. As the Infusorians develop, the smell will become increasingly sweet and the water will clear up. It will usually take 3-4 days for Infusoria to develop. When the water looks clear, you can start feeding your fry with the Infusoria. Use a siphon or a spoon to remove the Infusoria from the top of the jar and place it in your fry aquarium. Make sure not to bring any plant material from the Infusoria jars over to the fry rearing tank, since this can pollute the water. Start developing new Infusoria culture every 3-4 day to make sure you always have enough food for your fry until they are big enough to eat larger food.
