Goldfish Diet and Nutrition
Goldfish are natural omnivores, so a varied diet is an important factor in keeping goldfish healthy and disease free.
In the wild, goldfish feed on algae, plants, plant roots, worms, insects, larvae, tadpoles, small fish, snails and anything else they can fit in their mouths to taste and check if it’s ok to eat.
Although aquarium and pond goldfish are not wild and look nothing like wild goldfish, they have exactly the same digestive tract, and need the same sort of diet.
Feeding them flakes from a tin twice a day is not the way to do it.
Mealtimes
As stated above, it is best to try to mimic what goldfish would experience in the wild. As they would be almost constantly grazing, small meals are better than large meals. If goldfish are given a lot of food one or two times a day, they will pass most of it undigested. Goldfish do not have a stomach to hold food in while it is broken down, it just keeps on moving.
Dried Flakes, Pellets and Tablets
These types of goldfish food should be used as a base in their diet, but not as the only source of nutrition. The better ones will provide fibre, vitamins and minerals - as well as some quality protein, but they will not provide a varied diet.
Also, beware of flakes that are bulked up with cheap corn starch, or use cheaper vegetable proteins instead of fish proteins.
Another point worth noting is that dried foods swell up when they get wet. If they swell inside a goldfish, they may cause the swim bladder to be pressed out of shape, causing problems for the goldfish.
Frozen and Freeze Dried Food
These types of food are high in nutritional value, and there is plenty of variety. They are high in protein and contain all the amino acids that goldfish need for healthy muscles and tissue.
Freeze dried foods also need to be pre-soaked because, like dried food, they swell up when they get wet.
Live Food
Live food such as daphnia, freshwater shrimp and midge larvae is the most nutritional of all for goldfish. However there are a number of problems associated with giving live food to goldfish.
Firstly it is much more likely than any other goldfish food to carry disease or cause illness.
If worms or larvae are harvested from the wild, it is vital to ensure they do not come from ground that has been exposed to pesticide.
Secondly, they are harder to obtain than other types of goldfish food, and it is often necessary to breed them in separate tanks.
Finally some species of worm can disappear into gravel and set up home in an aquarium, causing problems for the goldfish and the aquarium.
Fruit and Vegetables
Certain aquatic plants can be grown in separate tanks and fed to goldfish, and they also enjoy a wide range of fruit and vegetables.
Make sure hard vegetables like carrots are cooked or finely grated, citrus fruit sections have the skin removed, things like peas and grapes are peeled, and softer items like lettuce and apple are chopped up. Fruit that is made of small constituent parts like raspberries can be dropped in whole, and the goldfish will pull the smaller manageable parts off.
One word of warning about fruit and vegetable - use them as treats and nibbles, not as a major part of a goldfish diet.