While all children develop at different rates, there are some basic things to keep in mind if you’re considering an aquarium for your child.
If your child is around the age of one or two, you may consider getting a “shelf pet” like a fish or hermit crab in a small tank rather than purchase an entire aquarium set-up.
These pets are contained and require little care. This is a great way to introduce the idea of a pet.
At this age, you may not want your child to do anything to take care of the pet, but they can watch you and you can explain what you’re doing.
When kids hit the Kindergarten age, typically age five, you can consider a larger aquarium. At this point, they can manage some of their tasks and may be ready to start caring for fish.
As they get older you can add more fish (perhaps you may need a larger tank) and the tasks they are responsible for.
Many times if a child can demonstrate he or she can handle taking care of a fish or other smaller pet, mom or dad will be more likely to give in to getting a larger pet.