Taking care of goldfish is traditionally viewed as something so simple even a child can do it. While that may be true to an extent, goldfish aficionados can attest to a complex feeding regimen designed to keep their goldfish colorful, healthy and long-living.
Goldfish are omnivores which means they can and will eat almost anything – meat or vegetable. Because a certain amount of their diet consists of vegetable matter, they need less protein than other aquarium fish. Because goldfish are always hungry, it can be easy to overfeed them. Although in an emergency goldfish can survive up to 2 weeks without eating, they should be fed twice a day the amount they can eat in 2 to 3 minute intervals.
Types of Food
The most common food manufactured for goldfish is flake food. Goldfish flake food is different than that made for tropical fish because goldfish nutritional needs are different. Flake food intended for goldfish will provide a good staple around which to build your goldfishes' diet. The Goldfish Society of America in its book, The Official Guide to Goldfish, (TFH 1996) advises goldfish enthusiasts, that if they feed only dry food, to feed two or three different kinds to provide variety in their fishes' diet.
Pellet food usually comprises the same matter as flake food but is compressed into pellets. Like some flake food, some pellet food contains only one type of ingredient, such as brine shrimp, which is meant to be a treat food rather than a staple. Check the labels before purchasing.
Goldfish enjoy live food, but few pet stores carry more than live brine shrimp. Cultivating live food is best left to the expert, as it can carry diseases which can harm your fish.
Frozen food provides your goldfish the benefits of live food with the added protection of being free of the diseases sometimes associated with growing live cultures. You can get frozen brine shrimp, daphnia, tubifex worms or mosquito larvae at a pet store. Frozen food comes most often in different-sized flat slabs, bits of which can be broken off and hand-fed to your goldfish without thawing the whole package. Store the unused portion in your freezer.
Homemade food or household foods give your goldfish variety and offer fresh nutrients to its diet. Some simple foods can be added relatively safely without danger to your fish or the risk of polluting your tank. If you are inclined to cook for your goldfish, a recipe for "gel food" is described below. Two of the easiest items to give your goldfish are lettuce and peas. Although goldfish will eat other types of lettuce, red leaf lettuce is easy for them to chew and unlikely to cause digestive problems. Rinse the lettuce in warm water then attach it to a lettuce-clip inside the tank. Don't cook the lettuce, however, as the lettuce may come off in strands and get caught in the goldfishes' throats.
Cooked baby peas are an excellent addition to your goldfishes' diet. Cook the peas until they are soft and refrigerate them. When it's time to feed a few to your goldfish, pinch off the skins, then slightly mash the pea between your fingers and drop it into the aquarium. Wait until your goldfish eats one pea to offer another. If you feed your goldfish peas that are too hard, he may develop bloat or other digestive problems.
How to Feed
How you feed your goldfish is as important as what you feed. Even flake food has to be "prepared" before dropping it into the aquarium. When a goldfish eats food that is floating on the water surface, it ingests air along with the food which often causes constipation, or impaction, from the food absorbing water in the intestines. Place the flake food in a small paper cup, dip the cup into the tank and fill it partially full of tank water. Swirl the food around a bit to saturate it causing it to sink when you drop it into the aquarium. Food that falls to the bottom will be ingested by your goldfish as it sucks material from the aquarium gravel.
Pellet food can easily become stuck in your goldfishes' digestive tracts, especially if you have fancy goldfish with rounded bodies such as an oranda, black moor, ryukin or other exotic varieties. Soak the pellets for 5 to 10 minutes until saturated before dropping them into the tank.
Recipe for Success
As a special treat, make your goldfish "gel food." Gel food is easy for you to prepare and easy for your goldfish to digest. Feed your goldfish the gel food only in conjunction with goldfish food that has been formulated for their nutritional needs.