Common / Comet Goldfish Stocking
Minimum 55 gal · 12" adult · high bioload · peaceful.
Estimated bioload
367%
overstocked
Bioload-based: it weighs adult size and waste output, not the oversimplified "1 inch per gallon" rule.
Advertisement
Keeping Common / Comet Goldfish
The Common / Comet Goldfish grows to about 12 inches and needs a minimum of 55 gallons. Its bioload is high, meaning it produces a large amount of waste for its size, a key factor the "one inch per gallon" rule ignores. It doesn't need a large group, but plan tankmates around its temperament. Temperament is peaceful, making it a good community fish. Use the calculator above to see how a group fits your tank's real volume before you buy.
Frequently asked questions
What size tank does a Common / Comet Goldfish need?
At least 55 gallons. They can be kept without a large group, but check tankmate compatibility.
Is the Common / Comet Goldfish peaceful?
Temperament is peaceful. Reaching about 12" as an adult with a high bioload, plan tankmates and filtration accordingly.
Keep going with the same pet
Not sure of your tank's exact gallons? Measure it with the aquarium volume calculator first.
Your dog's age in human years, breed-size adjusted, not the ×7 myth.
Your cat's age in human years using the real feline curve, not the ×7 myth.
How much to feed: daily calories and cups by weight, activity and life stage.
Tank gallons and liters from your dimensions: rectangle, cylinder, hex and more.