do comet/common goldfish need a 20 gallon tank i no they cant live in a bowl but what about a 5-7 gallon or even a ten gallon for one fish with basic siplise filter air stone ec. Posted on General ... http://www.myaquariumclub.com/care-and-keeping-of-common-comet-and-shubunkin-goldfish-4958.html · Reply. thea avatar. read more
The general rule of thumb for goldfish is actually 20 gallons for the first goldfish and 10 gallons for each additional fish so four goldfish would actually need a 50 gallon tank as opposed to a 40. And that is just the bare minimum. read more