A relatively small member of the carp family (which also includes the koi carp and the crucian carp), the goldfish is a domesticated version of a dark-gray/olive/brown carp native to east Asia (first domesticated in China) that was introduced to Europe in the late 17th century. Goldfish may grow to a maximum length of 23 inches (59 cm) and a maximum weight of 9.9 pounds (4.5 kg), although this is rare; most individual goldfish grow to under half this size. In optimal conditions, goldfish may live more than 40 years; however, most household goldfish generally only live six to eight years.

Ornamental fish can be used in Aquaponic systems quite happily. We have used goldfish for our small balcony kit and they survived wonderfully, the only issue we had was that the fish tank we used allowed the fish to jump out so had a couple of casualties.

Also use goldfish in the small kit I have in my kitchen. They love the company of the busy kitchen and I grow indoor plants in the five pots.