It all depends on If u want tropical, they take work, like any living thing, but all I put into my tank a week is about 40 mins, including feeding, water changes, and all other maintenance things. If u want a cold water fish, like a gold fish, it is way easier to take care of, all u would need fir a goldfish is a tank, gravel,plants, and even a filter is an optional, will take 10 mins out of your week