The goldfish is one of the “starter pets” of most people and most people who decide to keep fish. The goldfish is a beloved and iconic pet and easily recognized. With breeders creating a great variety of goldfish to be kept as pets, everyone knows what a goldfish looks like and can tell a few goldish stories. They are beautiful ornamental fish, but many people purchase goldfish thinking they are a nearly no-maintenance pet that has no special needs except a bowl, gravel and some cute aquarium accessories. Goldfish have some special needs and basic keeping skills need to be had by goldfish owners who want their goldfish to thrive and do its best.
Goldfish are descendants of and bred from the “chi” or “koi” fish kept in ponds by Chinese Buddhist monks starting in the 9th century. These were highly decorative large carp and their brilliant vivid colors and fins made them an attractive target for predators, so monks protected the more vivid carp. By the 13th century, decorative goldfish became a status symbol and were a way to show one’s wealth, far from winning them at a carnival! These domesticated goldfish were genetically different than their ancestors. Eventually, goldfish were kept indoors in bowls starting in the 1500s. This was done to show off one’s prettiest fish but was not good for the goldfish as it was in an unnatural habitat. The bowl-kept goldfish were chosen for being “fancy” and were spared from ever encountering predators and competition with their peers. This kept ornamental carp completely separate from the domestic goldfish.
While it seems goldfish are short-lived, fragile pets, when housed correctly and properly cared for a goldfish can live up to 20 years. Goldfish do not get as big as their tanks allow them to grow and in a correct and adequate aquarium, a goldfish will thrive and provide grace and beauty to your home for many years. The original goldfish bowls were large ceramic basins and not the mass-produced 1-gallon tanks most people place a goldfish in and expect it to do well in.
If you want to showcase and enjoy the swimming dance of your pet goldfish, it requires a spacious home. Ideally, a goldfish should start in a 75- to 100-gallon tank. Goldfish are a carp, so depending on their breed, C. auratus will reach a size over a foot long, but sadly, few goldfish reach full adult size in a fishbowl. A goldfish keeper should allot 20 gallons for each goldfish and as they grow can avoid upgrading their tank by starting with a large tank that provides 20 gallons of space per fish.
Goldfish also need a big tank to ensure the water does not become the disgusting ammonia nose-hair curling mess and prevents “burials at sea” because pet owners do not keep the aquarium clean. Goldfish are not tidy or dainty eaters, nor do they have any bathroom manners. They will let food sink or get missed and will poop whenever they like and often in their homes. The solid waste of food and fish poop will be broken down by microbes and creates toxic by-products. The larger tanks allow you to have an aeration and filtration system in your goldfish tank and dilutes the metabolic by-products. Goldfish are happiest at 68 degrees and while they are rugged and survive in many climates, a tank kept at 68 degrees is healthiest for them. A large volume tank ensures the temperature is even.
Goldfish need a powerful aquarium water filter. A full-sized canister filter is ideal. Hanging filters can only be good for a goldfish is they are powerful enough to keep the water clean. The goal is to not create movement in the water but to remove particulates from it. Fancy goldfish are not strong swimmers due to their outsize and extra fins and cannot tolerate currents that will suck them into a filter. A bubbler is necessary to circulate the water gently and provide oxygen to the water. The fancier fish like the beloved bubble-eye requires gentle filters and a bubble wand aerator that keeps the water calm so they can glide in it. Goldfish prefer their water to be slightly alkaline. A tanks’ water should have a pH between 7.0-7.4 for healthy happy fish.
Goldfish are omnivores and will eat anything given to them. They will also overeat if allowed. Goldfish do not have a developed enough brain to know when they are full and will eat themselves to harm if given all the food they will eat. They need specially formulated goldfish foods, never in excess, and only be given an occasional treat. Goldfish need a high carbohydrate-to-protein ratio food. Once or twice a day tops, give your goldfish only all the food they can consume in a two to three-minute marathon meal. Any remaining food should be removed from the tank so that it doesn’t contaminate the water. To ensure a well-fed and nourished goldfish, remember they are bottom feeders, so pre-soaked food will sink and provide them with an activity you can observe and enjoy as they eat. Gulping food particles floating on the water surface causes fish to have their equilibrium and air bladder upset so they swim upside down. Take a cup of tank water and swish their meal in the water and add it back to the tank to soak it for them and prevent disoriented air-swallowing fish.
Goldfish décor is fun. Goldfish need gravel that is larger so they can avoid eating it when swimming along the tank bottom looking for a snack they missed. Sand and fine gravels can accidentally be ingested by a grazing goldfish. Many people add too many accessories such as tank sculptures and fake plants that minimize the swimming area. Minimal décor and not using live plants are best. Goldfish are notorious about eating or destroying live tank plants so inedible plants such as anubias or java ferns are best if you insist on providing it live plants for décor. The goldfish do not need plants or a castle to play in. It needs space to swim in.
By following these simple fish care rules for freshwater goldfish, your goldfish will be providing meditative, graceful displays and family enjoyment for several years.