General container for holding water, such as a storage tank or a cistern.
A large water tank is installed on the rooftop.
fish tank; aquarium
Specifically a tank for keeping fish or aquatic life, such as a home aquarium or a public display tank.
熱帯魚を水槽で飼っている。
I keep tropical fish in an aquarium.
I keep goldfish in a tank.
I put new fish into the tank.
I change the tank's water every week.
I clean the tank once a month.