neutral to alkaline pH, moderate to very hard water
10 to 30°C (ideally 15°C to 24°C)
Telescope goldfish have distinctive “bulging” eyes but are otherwise similar to fantails. Black moors are telescope goldfish with jet black bodies. These blackfish always have telescopic eyes, but telescopic eyes can also occur in fish of other colors (eg, red, white, calico). Telescopes have quite poor eyesight and may have trouble finding food, so it is best not to mix them with faster-moving varieties. Except in very cold climates, they can tolerate outside temperatures and so be kept in ponds. However, they are much slower swimmers than comets, so may be susceptible to predation by birds or cats where these are present.
Good specimens should have a body shape like that of the fantail, well-matched telescopic eyes, and well-developed finnage. The tail and anal fins should be double and separate all the way to the body. Ideally, the paired fins should be well-matched and free of any kinks.