The Complete Goldfish Tank Setup and Care Guide

Ornamental fish-keeping, as a hobby, has been around for several thousand years. Hobbyists may choose from a variety of freshwater and marine species to keep as pets in an aquarium or fish tank. It not only serves to beautify its surroundings but also acts as a great stress-reliever. An indoor water body such as an aquarium, if kept correctly, is also considered auspicious in Indian Vaastu Shastra and Chinese Feng-Shui.

Of the hundreds of species of ornamental fish available, Goldfish are the probably most popular and most loved variety. They are colourful, playful and come in various shapes. They are also relatively inexpensive to buy and are easily available at pet stores and markets. However, contrary to popular belief, Goldfish are not the easiest to keep or maintain. Although they are relatively tough and have long life-spans, they require clean water and good quality food to thrive and are, therefore, not recommended as beginner fish.

Goldfish can be segregated into two broad categories:

a) Common Goldfish – Also known as Comets, they are slim-bodied and fast swimmers. They can grow up to or more than a foot in length and best kept in outdoor ponds. They are inexpensive to buy and are much more tough than fancy goldfish; meaning, they can tolerate moderate changes in water temperature, pH, salinity and dissolved wastes.

b) Fancy Goldfish – There are more than a hundred species of fancy goldfish. The most popular ones are Fantail, Red Cap Oranda, Black Moor, Bubble Eye, Ryukin, Pear Scale, Lion Head, Ranchu and Celestial Eye to name a few. They typically have an egg-shaped body with long flowing fins although some varieties may have shorter fins, larger eyes or rounded heads. They are slow swimmers and are ideal for indoor aquariums and fish tanks. They may grow up to 8 inches and live for 5-10 years if cared for properly. However, these varieties are more expensive than the common goldfish and require very clean water and good quality food.

Goldfish, in general, are very docile and sweet-natured and bond well with other varieties of Goldfish and non-aggressive fish. However, in order to maintain compatibility with water quality requirements and feeding habits, it is best advised to keep only Goldfish in an aquarium or tank. The following list details all the items necessary for setting up a new Goldfish tank from scratch:

1. An aquarium, preferably rectangular and made of glass, with the longest side measuring at least 2 feet in length. Goldfish are an active species and require lots of space to swim. It is recommended to provision at least 10-12 gallons of water per fancy goldfish although the ideal volume would be 20-25 gallons of water per fancy goldfish. Such a high volume of water is needed not just for swimming but also for diluting dissolved waste concentration.
2. A high-capacity filter with a flow-rate roughly equal to 8-10 times the volume of the entire tank. Internal power filters, hang-on back filters, top filters and canisters are all suitable for a Goldfish tank. Selecting the right type would depend on the aquarium size and setup. Goldfish are messy eaters. They eat a lot and excrete a lot. Hence, the need for a high level of filtration.
3. Filter media such as sponge, bio-balls and activated carbon.
4. Aged and cycled fresh-water (tap water). Setting up a new tank and immediately putting fish in it is akin to torture. It is necessary to complete a fish-less cycle with the water by putting a piece of organic matter (e.g. raw shrimp) in it and letting it stand for 3-4 weeks. This will create a colony of beneficial bacteria in the water which will break-down the organic matter and complete the nitrogen cycle without harming your beloved goldfish. If possible, submerge the filter in this water so that the beneficial bacteria may colonize the filter media. This step is absolutely essential for cycling your tank and preventing unintended casualties in future.
5. Water-proof aquarium lights, preferably full-spectrum and led-based.
6. Thermocol or Polystyrene sheets to be placed underneath the aquarium for supporting the weight of water and to prevent cracks in the glass base.
7. Seachem Prime or any other dechlorinating agent. Chlorine is harmful for fish as it burns their gills. If you don’t have a dechlorinating solution, let the water stand overnight, uncovered, before putting it inside the tank. The dissolved chlorine shall evaporate, making the water safe for use.
8. Seachem Cupramine or any other anti-ich treatment. This is necessary for disinfecting fish from external parasites and ich. Put your new goldfish in cupramine-treated water for at least 15-20 minutes before placing in the main tank.
9. Good quality fish food, in the form of pellets (sinking or floating) and/or flakes. Hikari Goldfish Gold, Saki-Hikari Fancy Goldfish Colour-Enhancing, Saki-Hikari Fancy Goldfish Balance, Sinking Goldfish Excel and Hikari Oranda Gold are some good options. If you prefer a clean tank, floating pellets are the best bet although some hobbyists are of the opinion that this might cause swim bladder issues. Sinking pellets are equally good but may cause water-quality issues if left uneaten.
10. Rock-Salt for reducing fish-stress and for treating internal parasites.
11. Decorations, such as pebbles, gravel, porcelain show-pieces, fake plants, etc. It is recommended to keep a bare-bottom tank or one with minimal decorations for fancy goldfish such as Orandas and Pear Scales. A clean bottom will prevent accumulation of waste and aid in easy clean-up during weekly water changes.
12. Background vinyl wallpaper to beautify your aquarium with minimum decorations.
13. Thermometer; digital or analog to measure water temperature and observe fluctuations in the same.
14. An air-pump, airline tubing and air-stone to oxygenate the tank or for emergency treatment of sick fish. Also stock an air-flow controller valve if you wish to control the intensity of air bubbles.
15. Magnetic scrubber for cleaning the glass walls.
16. Fish net to transfer the goldfish between tanks.
17. Siphon for water-change activities.

Once the aquarium is set up and running with the goldfish in it, we need to start taking care of our pets. Maintenance does not require much time but one has to be consistent and punctual. The following list covers the most common activities:

1. Feeding: Feed your goldfish daily, at least 2-3 times a day if they are young (less than a year old) or once, if they are adults. During each feeding, care should be taken to ensure that the goldies are not over-fed. Feed each fish the quantity of food that is roughly the size of their eye or that which can be completely eaten by each goldfish within 2 minutes. Remove any excess food from the water as it may degrade water-quality by polluting the environment. For example, you may feed a 3-inch goldfish up to 5-6 small pellets per day. Split the quantity to be fed, twice or thrice during the entire day. Slightly under-feeding shall not harm the goldfish as they are known to live without food for up to 2 weeks. However, over-feeding can cause bloating, constipation and swim-bladder issues.
2. Water Change: At least 50% of the water should be changed every week to remove pollutants and dilute the concentration of growth-inhibiting hormones. A siphon may be used to drain the polluted water and also to vacuum the base of the tank to suck up fish-poop. However, do not remove all of the tank water as it contains beneficial bacteria and complete removal may upset the delicate nitrogen cycle of the aquarium. Refill with tap water and add a suitable dechlorinating agent such as Prime. One should be careful regarding the dosage since excess use of chemicals is harmful for fish.
3. Salinity & pH: Add one table-spoon (3 tea-spoons) of non-iodized rock-salt for every five gallons of water. This shall reduce stress and prevent several goldfish diseases. For temporary treatment of severely sick fish, prepare a separate 5-gallon salt bath by adding 10 table-spoons (30 tea-spoons) of rock-salt for every gallon of water. Place the sick goldfish in it and observe for 5 minutes. If the goldfish act a bit odd, that is normal and is due to the high salinity. But if they roll over and cannot stay upright, remove them from the salt bath and keep them in a hospital tank with less dosage of salt or with proper medication. Goldfish do well in the pH range of 7.2 – 7.6, that is, slightly alkaline water, and care should be taken to maintain the same.
4. Hiding Places: Goldfish sometimes need quiet places to hide. Use only blunt decorations and remove anything, including fake plants, which may tear or damage fins.
5. Fish Behaviour: Check the behaviour of your goldfish periodically. Gasping at the top indicates a lack of dissolved oxygen. The remedy is to increase oxygen or air-bubbles with an air-pump. Bottom-sitting is a sign of stress or internal parasites. Add rock-salt or suitable medication. White-spots on the body or rubbing against glass walls may be an indication of ich. Separate the affected fish in a hospital tank and treat with salt and/or cupramine solution. Sudden jerks, spams, erratic movement or red-veins may be a sign of ammonia poisoning. In such a situation, frequent 50% water-changes may provide relief. Last but not the least, looks for signs of aggression. Although rare, aggression may sometimes be noticed due to competition arising out of lack of adequate food or lack of space due to over-stocking. The remedy would be to remove the aggressor, increase food quantity and/or reduce stocking.
6. Light & Sound: Goldfish need at least 8 hours of daylight to stay active and maintain their colour (pigmentation). Direct sunlight is not recommended as it increases water temperature. Instead, use full-spectrum led aquarium lights to beautify your tank and aid your fish in maintaining their day-night cycle. Please note that goldfish also need to rest and/or sleep. Hence, 8 hours of darkness or shade per day is also necessary. Care must be taken to ensure that the goldfish are not subject to extremely loud noises.

Goldfish make excellent pets. They are cute, playful and come in various colours. Taking good care of them if the least that we can do. I really hope that this article shall help a lot of Goldfish owners or those who are planning to keep some as pets.