[FishyFishy89]

Sorry, no. Goldfish get quite large, even the plump cuties get very plump. And they need atleast 1 other goldfish of their same species (ex fantail with fantail) to be happy. A 20 gallon simply won't hold 2 adult goldfish comfortably.

The general rule for goldies is 20 gallons for the 1st and 10 gallons per every other goldie.