An aquarium is like a fish house where fish can live and play. It's a big glass box that has water in it and you can see through it. The fish swim around and you can watch them.
The aquarium is usually filled with water from a special tap that makes the water clean and safe for the fish to live in. The fishes' home is decorated with rocks, plants, and plastic treasures for them to explore and feel comfortable in.
The water in the aquarium is kept clean by a special machine called a "filter" that makes the water go through some special material that catches any dirt or yucky things. This makes the water clean and healthy for the fish.
Fish eat special food that comes in small pellets or flakes that float on top of the water. Some fish eat small bugs or other fish.
Aquariums are fun to have because they provide a peaceful and relaxing environment and watching the fish swim around can be very calming. It's important to take good care of the fish and their home by cleaning the water and feeding them regularly so they can stay happy and healthy.