Dive into Goldfish Care: A Beginner’s Guide

Goldfish are extremely popular as pets as far as fish go and make a great addition to any aquarium. These intelligent, social marine animals can recognize their owners and bond well!

As domesticated water creatures, goldfish require proper care to thrive! Every aspect needs attention to detail to keep this fish happy and healthy.

This blog post is a beginner’s guide to caring for your goldfish.

Origins of the Goldfish

Dive into Goldfish Care

Carassius Auratus, known as the Goldfish, originated from Eastern Asia and was initially consumed as food. However, a thousand years ago, domestication of this species started in China.

There are a variety of Goldfish present such as:

  • Fantails
  • Orandas
  • Black moors
  • Ryukins
  • Pearlscales
  • Wakins
  • Ranchu
  • Telescope eyes
  • Bubble eyes
  • Celestial eyes
  • Shubunkins
  • Comets
  • Butterfly tails
  • Lionheads
  • Tosakins

These pets are high in demand and sport beautiful appearances, with several colors, patterns, and fin styles. Fancy goldfish are the most popular due to their unique and aesthetically pleasing looks, but of course, appearance is not the only aspect to look for when choosing a goldie.

Before bringing one home, make sure that the goldfish is healthy. You can ensure its health by observing the fish in its tank. If the fish appears to be actively swimming around with erect fins, it will likely be healthy. The fish should also be responsive and swim to you when you approach the aquarium. Examining the fish for any white dots or torn fins is important. You can also ask the caretaker if the goldfish has had any infections. With considerable care, your pet will likely be your companion for 20-30 years. Keep reading to discover more about their temperament.


Smart and social, the goldfish are compatible with most fishes that are calm and similar in size. They like to stay in groups, so keeping multiple goldfish in a tank is advisable. These fish are slow swimmers, so ensure they are in a calm environment and in the company of peaceful marine creatures.

Goldfish are friendly pets that can be trained to be hand-fed. Handfeeding allows for a great opportunity to bond with your goldie!

Before you take one home, knowing everything you will need to keep your goldfish thriving is important!


Ensure you have the following supplies available before you bring your goldie home.

  • Appropriately sized tank
  • Food, dry and frozen
  • Decor and accessories
  • Water conditioner and filter
  • Water test kit
  • Full spectrum lighting
  • Net
  • Thermometer
  • Freshwater substrate
  • Refractometer
  • Aeration system
  • Check valve
  • Freshwater salt

While this may seem excessive, these supplies play an essential role in caring for your fish. We will further explore these in our next section, which provides effective guidance for goldfish care.

Caring for Your Goldfish

Dive into Goldfish Care

A big chunk of caring for these species is related to their habitat and its different aspects. Their diet, breeding environment, and health concerns are other areas that you must explore to ensure your pet is healthy and safe.

Housing and Tanks

Out in nature, goldfish are found in almost all types of freshwater bodies. These fish can live in cold waters and heated tanks when domesticated.

When housing your goldfish, choosing an appropriate aquarium size is crucial.

You can also keep some goldfish in outdoor ponds, like common goldfish, Comets, and Shubunkins. Avoid keeping fancy goldfish like Orandas, Ryukins, and Moors, as they are more susceptible to being attacked by predators.

Suppose you plan to keep your goldfish indoors. In that case, we recommend using a rectangular aquarium instead of a fishbowl, as they need sufficient room to swim and produce waste in huge quantities. Spherical containers can also stress out the fish as the surroundings appear distorted due to refraction.

The tank size should be large enough to accommodate your pet and have necessary equipment and accessories like filters, aeration systems, plants, and decorations. Your goldie should have plenty of room to swim and grow, as adult goldfish can grow to be as big as 12-18 inches.

Water Specifications

Building a safe home for your goldfish requires the right water to flourish this aquatic life. The water should be oxygen-rich and well-aerated through aeration systems, besides being clean and fresh.

One of the main reasons why aeration is important is that it helps to maintain adequate oxygen levels in the water. Fish and other aquatic organisms require oxygen to survive, and without adequate oxygen levels, they can become stressed, sick, or even die. Aeration helps increase the dissolved oxygen content in the water, making it easier for fish to breathe and ensuring they remain healthy and active.

A vital aspect of caring for this fish is ensuring cleanliness through filters and water test kits, which can detect pollutants otherwise invisible to the human eye.

High amounts of ammonia and nitrate are hazardous for this species. These emerge when the tank is improperly maintained or the water is dirty. Bottled, tap, or reverse osmosis water is recommended.

Dechlorinating the water is highly important as chlorine is fatal for goldfish.

Make sure to use water conditioners to treat tap water before refilling.

Other water specifications to keep in mind are:

  • Temperature: 68°-74° F for fancy goldfish. 60°-70° F for larger ones like Comets and Shubunkins. Use thermometers to ensure the temperature doesn’t fluctuate more than 2 degrees.
  • pH: 7-8.4. Not too pressing.
  • Amount of water: 20+ gallons

Note: Dirty water and poorly kept aquariums can lead to infections and serious illnesses. Check the water temperature daily and ensure filters and other equipment function properly. Use the water testing kit every week, and change 10-25% of the water twice a week.



Besides keeping the tank clean, filtration systems are important to induce slow currents through the water. It helps mimic their natural habitat and leads to better health. Filters are also necessary to control waste management.

The three most common filtration methods are:

  • Mechanical: It involves cleaning your aquarium by removing particles and dirt from the tank. This type of filter must be removed and cleaned at least once a month.
  • Biological: These filters use bacteria to break down waste and convert harmful substances into less toxic elements. Also known as the nitrogen cycle, this process is an essential step in ensuring the health and safety of your goldfish.

The cycle consists of bacterial colonies converting the highly toxic ammonia into nitrates. Before you add your goldfish to the aquarium, the test kit should show the final readings:

  • 0ppm ammonia
  • 0ppm nitrite
  • and 5ppm to 20ppm nitrate

This filter must also be checked and cleaned to avoid contamination.

  • Chemical: This filtration method uses chemicals like activated carbon or filtering resin to cleanse the water and remove hazardous waste.

Note: It is ideal to have a filtration system that uses at least two of the filtration methods mentioned above.

When it comes to choosing the right filter for your aquarium, it is important to know the different varieties that exist:

  • Sponge filter: It helps establish essential bacteria and controls waste.
  • Cartridge filter: The ultimate choice for bigger aquariums. It keeps the water clear and odorless.
  • Hang-on-back filter: These are placed outside the tank; this filter effectively keeps the water clean and provides surface aeration.
  • Submersible filter: One of the most popular filters, and includes a strong current generator and sponges.
  • Under gravel filter: This filter helps remove waste from under the surface. However, it is less effective when used alone.
  • Sump system: You canachieve perfect filtration with this system, consisting of an additional space that combines different filtration methods and equipment.
  • Canister filter: While these filters do not actively remove waste, they keep the water clean as they hold filtration materials.


Dive into Goldfish Care

You can beautify the aquarium and provide a safe, homely space for your goldfish with minimal yet aesthetic aquatic decorations. As goldfish are prey animals, enhancing their tanks with plants, rocks, and caves that give a sense of shelter is a great idea.

Refrain from using accessories with sharp corners to prevent injuries. Remember not to overcrowd the aquarium and leave enough room for your goldfish to swim freely.


Dive into Goldfish Care

Innately omnivores, goldfish consume a mixed diet of plants and insects in the wild. In captivity, these pets require a diet rich in carbohydrates, so it is best to opt for goldfish-specific foods. Insects are a great source of protein, while plants and vegetables improve digestive health.

For a well-balanced diet, you can feed the following items to your goldfish:

  • Formulated pellets and flakes
  • Freeze-dried foods
  • Daphnia
  • Brine shrimp
  • Mosquito larvae
  • Tubifex worms
  • Bloodworms
  • Algae wafers
  • Deshelled peas
  • Romaine lettuce
  • Cucumber
  • Carrot

Do not feed dry flakes or floating pellets, as gulping air can harm goldfish. Feed them once or twice a day and ensure they can consume the food in 2-3 minutes. Overfeeding can cause serious health issues.  

Common Health Issues

Goldfish can be vulnerable creatures, prone to several infections and diseases. A healthy fish has clear eyes, a normal appetite, and regular breathing. If you notice your fish displaying any of the signs mentioned below, immediately contact your veterinarian:

  • Low appetite
  • Loss of color
  • Spots or fungus
  • Breathlessness
  • Weakness
  • Cloudy eyes
  • Erect scales
  • Bloating
  • Discolored fins
  • Weight loss

These signs indicate diseases that need medical attention and can result from some prevalent diseases in goldfish.

Ich: Common symptoms are white spots, rapid breathing, erratic swimming, and body rubbing against objects. Isolate the suspected fish in a separate tank and add aquarium salt. Contact your vet for commercial relief.

Bacterial infections. Common symptoms are cloudy eyes and red skin. After checking the water quality and adding aquarium salt, consult the vet for antibacterial treatment.

Fungus: Discoloration in eyes and white, cotton-like growth are common symptoms of this disease. Quarantine your goldie and seek medical help. Use an antifungal medication as recommended by your vet.

Fin rot: Immediately consult your vet for treatmentif thefins start to wear out and their base becomes red.

Ammonia poisoning and stress: If you were wondering why your goldfish is turning black, now you know the two main culprits behind it. Try to create a stress-free environment for your goldfish by keeping the temperature and other water parameters in check.

Also, check the water with a test kit for ammonia poisoning. If the level is above 0 ppm, the patches may have appeared due to excessive ammonia.

With this comprehensive guide, you can better understand the level of care that goes behind keeping a goldfish as a pet.

While it may seem overwhelming initially, things become more manageable once you have set up your tank. We highly recommend getting these aquatic creatures as pets. Not only do they look beautiful, but having one around can also be therapeutic.

Adam Hill

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