Non-poisonous jellyfish, such as Moon jellyfish and Blue Blubber jellyfish, are widely available and appropriate as pets for children. Pet jellyfish for kids require a special aquarium and fish-specific diets.
Specialized jellyfish aquariums pull the water through the rocks at the bottom of the tank. They then suction the water up to the top of one side of the aquarium before releasing the water back down on the opposite side of the tank. This design ensures that the jellyfish, who spends most of its time floating with the current, does not get sucked into the aquarium's filtration system.
Moon jellyfish are fairly large, white, bell-shaped jellyfish that must be fed a diet of frozen or freeze-dried phytoplankton or fresh brine when in captivity. These types of jellyfish grow up to 2 to 5 inches in diameter and thrive in waters ranging between 70 to 80 degrees Fahrenheit.
Blue Blubber jellyfish have eight arms instead of the long, dangling tentacles found on other types of jellyfish. They can grow up to 18 inches in diameter. These types of jellyfish also eat phytoplankton or brine, however, some of their diet is self-manufactured through a photosynthetic process that allows them to store and eat unicellular algae.