What Is Stunting a Goldfish's Growth?

Goldfish grow according to their tank size, and larger aquariums or ponds will result in larger fish. At minimum, young goldfish require five to 10 gallons of water per fish to grow to their full size. As the fish grow larger, they will require substantially more space. Plan on giving larger goldfish at least 10 gallons of water for every 2 inches of length.

Overcrowding dramatically decreases the space available for your goldfish and may stunt growth. Crowding can also make it difficult for your fish to get enough food, and may cause some fish to behave aggressively toward smaller fish. If you see your fish fighting over food, chasing one another or hiding, your tank may have too many fish for its size.

Goldfish are omnivorous scavengers in the wild, which means they will eat just about anything and need variety in their diets. While fish flakes provide adequate nutrition, they are often not ideal nutrition and rarely will allow your fish to grow to her full potential size. Try adding brine shrimp, fresh fruits and vegetables and small pieces of cooked meat, such as chicken or beef, to your fish's diet.

Goldfish live in cool lakes and streams, but water that is too cold will stunt their growth. Goldfish take their behavioral cues from the environment, and in water 55 degrees and under, they may stop eating. Ideally, your fish's tank should be between 65 and 75 degrees Fahrenheit. Fish also need ample lighting. Without a daily light cycle, fish may turn pale or white, lose their scales or stop eating. Give your fish 12 hours of light per day.