Comet Goldfish Stats Minimum Tank Size: 55 Gallons (75 Gallons recommended) Care Level: Easy Water Conditions: 6.5-7.5 (Soft to Hard) Temperature: Optimal Range 10-24 °C (50-75 °F) Upper Range 24-30 °C (75-86 °F) Maximum Size: 13 inches (33 cm) The comet goldfish is one of the oldest and best known variants of the common goldfish. It was first bred in the late … [Read more...] about Comet Goldfish – The Care, Feeding and Breeding of Comet Goldfish