I'm intending to buy two goldfish. What type of tank will be best for them?
Although the goldfish bowl with its narrow top has largely disappeared, you can unfortunately still buy circular tanks, which do not provide adequate swimming space for these active fish, compared with a rectangular tank.

The best option is to choose a relatively large aquarium at the outset, at least 24in (61cm) long and preferably 36in (91cm), so that it will not be necessary to move the goldfish repeatedly as they grow larger. Bear in mind that goldfish are long-lived fish, with a life expectancy of 15-20 years, and can occasionally live into their forties.