To grow infusoria, fill a wide mouthed glass or clear plastic container with water. Add a piece of crushed banana peel, apple peel or crushed lettuce and set under sunlight. After a few days or so, the water will get turbid and stink a little and that's infusoria. Start the culture when you first see the bubble nest. Add a tablespoon or two to your fish tank each feeding but don't over do it. Same way for the green water until the fry can take the brine shrimp. Good luck.