How to set up an aquarium (for goldfish): 10 steps

Table of contents:

How to set up an aquarium (for goldfish): 10 steps
How to set up an aquarium (for goldfish): 10 steps

Properly welcoming a goldfish into your home and providing it with a suitable aquatic shelter is no small thing. Your goldfish will soon become part of your family and will start spending time with your closest friends. Therefore, you must make sure that your goldfish is happy, comfortable and that above all, it has nothing to complain about the aquarium that you keep.


Part 1 of 3: Choosing and equipping an aquarium for goldfish

Set up a Fish Tank (for Goldfish) Step 1
Set up a Fish Tank (for Goldfish) Step 1

Step 1. Consider the size of your aquarium

Goldfish require a particularly spacious home to stay healthy. Although they are very small fish, they need larger aquariums than you might expect.

  • It must be more than a bowl. Despite the beauty of a goldfish suspended in a glass sphere, most fish tanks simply do not provide enough space for their occupants.
  • You can keep a single ornamental goldfish in a 10 gallon (38 liter) aquarium, but larger goldfish like comets need one that is around 50 gallons (189 liters).
  • If you can prevent a goldfish from “taking over” and want to allow it to have a friend with whom to cope with its captivity, it will be necessary to increase the capacity of the aquarium (more or less by 38 liters or 10 gallons) for each additional fish.
  • A 20 gallon (76 liter) aquarium is ideal for your first goldfish and can hold 2-3 ornamental goldfish.
Set up a Fish Tank (for Goldfish) Step 2
Set up a Fish Tank (for Goldfish) Step 2

Step 2. Decorate your aquarium

Most goldfish prefer a palace or castle setting. Try to find something in between. Gravel is a must and plants are recommended. Therefore, your choice of decoration, gravel and plants must follow certain guidelines:

  • Choose a suitable gravel for goldfish. Don't use real gold chunks as they will likely be dangerously small. Goldfish are scavengers. They pick up chunks of gravel and tinker with them just for fun. Use gravel that is made from chunks that are too large for fish to swallow.
  • Definitely attract your goldfish with wide rocks, caves or plants. They like adventure and can easily think that they are not in an aquarium.
  • Don't use wood. It looks spectacular, but it will paint the water and depending on the type of wood, it will dissolve.
  • Be aware that some rocks and seashells will affect the pH of the water. If you add anything you find on the beach, you will need to check the pH frequently.
  • Only place certain plants in the goldfish tank. These curiously are very aggressive with plants. Some of these can be better defended:

    Try the types of vallisneria, the different hygrophilas, the red bacopa or even the ludwigia arcuata

Set up a Fish Tank (for Goldfish) Step 3
Set up a Fish Tank (for Goldfish) Step 3

Step 3. Use a filtration system

The filter is an indispensable component of your aquarium. Filters operate according to the flow of water and certain filters are designed for aquariums of certain sizes, so be sure to purchase the correct filter for the size of your aquarium. There are two types to choose from.

  • The external filters rest on the outside of the aquarium, while the internal filters are submerged inside the aquarium. Any type of filter can work for a goldfish aquarium.
  • External filters are generally considered superior as they have a greater capacity to store filter materials and consequently can clean the water more thoroughly.
  • If you have a 76 liter (20 gallon) aquarium, find a suitable filter for 151 liters (40 gallons).
Set up a Fish Tank (for Goldfish) Step 4
Set up a Fish Tank (for Goldfish) Step 4

Step 4. Add conditioned water

You can use tap water to fill the tank, but you need to add a conditioner to make it safe for your goldfish. At the very least, you need a conditioner that neutralizes chlorine and chloramine.

  • Aside from removing harmful chemicals from tap water with the conditioner, you also need to make sure that the water has the proper pH level for goldfish, which is a slightly alkaline pH of 7 to 7.5. Use a water kit. pH test to regularly evaluate the water and adjust the pH if necessary.
  • Take your aquarium location seriously. Do not place it near a window or in any source of heat or cooling. Do not allow sunlight to hit the aquarium directly. Also make sure to set it on something flat and very sturdy.
  • You probably don't need a heater. The temperature of the aquarium water should be between 16 and 22 ° C (60 and 72 ° F), so with the room temperature of your house it will be sufficient.

Part 2 of 3: Cycling Your Aquarium Water

Set up a Fish Tank (for Goldfish) Step 5
Set up a Fish Tank (for Goldfish) Step 5

Step 1. Allow the water to acquire healthy bacteria before adding the fish

When you first set up an aquarium, you need to let the water settle for at least a few weeks before showing the place to any potential occupants. This period is necessary to help grow beneficial bacteria, a process that we describe in this section. You must be patient during this process.

Set up a Fish Tank (for Goldfish) Step 6
Set up a Fish Tank (for Goldfish) Step 6

Step 2. Change the water in the aquarium once a week

Let's face it, goldfish defecate a lot. Also, they loathe swimming around their own feces, as anyone would. Their feces will accumulate dramatically in the aquarium water (even with many water changes), which will enrage and make your goldfish sick. To stop this accumulation, change between 25 and 50% of the water in the aquarium once a week.

  • When changing some of the water in the aquarium, rinse the filter and any decorations with water that you remove from the aquarium. Never use tap water. The healthy bacteria that you want to preserve live in these items.
  • Just add clean water that you have treated with the water conditioner.
Set up a Fish Tank (for Goldfish) Step 7
Set up a Fish Tank (for Goldfish) Step 7

Step 3. Cycle the aquarium water once a month

You should also regularly cycle the aquarium, that is, change 100% of the aquarium water. The purpose of cycling the aquarium is to allow it to re-develop colonies of beneficial bacteria, which mainly accumulate in filter and gravel. These bacteria help the water to cycle nitrogen, which is necessary to keep fish alive.

  • Once the aquarium is installed and ready to go (with the filter running), add the ammonia. Keep adding ammonia until enough bacteria have grown to eat both the ammonia and nitrites in the aquarium.
  • There are several forms of ammonia, which is most available in a bottle. Follow the instructions on it.
  • Determine levels of ammonia, nitrites, and nitrates using test kits designed for this purpose.
  • Continue the process until you get readings that indicate zero ammonia and zero nitrites. Once you also find some nitrate in the water (which bacteria produce), your aquarium will be properly cycled.

Part 3 of 3: Introducing your goldfish to its new home

Set up a Fish Tank (for Goldfish) Step 8
Set up a Fish Tank (for Goldfish) Step 8

Step 1. Choose an occupant for your aquarium

Find a healthy and beautiful fish. Don't choose one from an aquarium that also has sick or dead fish. You should select a fish that appears aware of its surroundings, moves actively, nibbles on things, and generally acts like it is the boss.

  • Take a good look at the goldfish's eyes, as they should be clear, not cloudy.
  • Check their fins and body. Look for a fish with erect and not ragged fins. Fallen or damaged fins often indicate poor health. Also, don't choose a fish with white spots, fuzzy spots, or red stripes.
  • Once you've made your choice, place your fish in a plastic bag filled with water from the aquarium it came from. Tuck the bag into a paper bag so the journey to his new home doesn't traumatize him.
Set up a Fish Tank (for Goldfish) Step 9
Set up a Fish Tank (for Goldfish) Step 9

Step 2. Show him your new home

But don't rush the process. Float the bag for 15 minutes in the aquarium to allow the fish to slowly acclimate to any difference in temperature. After 5 minutes have passed, allow some water from the aquarium to enter the bag, but do not allow the water from the bag to enter the aquarium.

  • Do not pour the fish and the water from the bag into the aquarium. Rather, carefully remove the fish from the bag with a net and slowly submerge the net in the aquarium, letting the fish swim out of the net on its own.
  • Turn off the lights and leave the room. Give your new goldfish some peace and quiet to find its new home.
  • Add an aquarium additive called "stress coat" to the water to minimize the risk of your fish getting sick due to the change in environment.
Set up a Fish Tank (for Goldfish) Step 10
Set up a Fish Tank (for Goldfish) Step 10

Step 3. Feed your goldfish as if it were your only friend

There are many different options. Choose the one you prefer. Preparation is the most important thing. If the food is dry (most goldfish foods are), soak it in aquarium water for 1 minute before feeding it to your fish. Unsoaked food can hurt or make fish sick as it expands in its stomach.

  • Fish food should sink or stay suspended in the water. Floating food risks causing bladder problems in the fish.
  • Feed him once a day, six days a week. On the seventh day, the goldfish needs to rest.


  • Here are some ways to speed up the cycling process:

    • During this process, keep the water slightly warmer to increase the rate of bacteria growth.
    • You can buy a bottle of bacteria ready to go. If you choose this option, you should still wait to add some ammonia and test until the tank is balanced.
    • You can ask a friend for bacteria who already has a well established, freshly cycled aquarium. Spread them around your aquarium by taking some of its gravel or by cutting a piece of its filter sponge and adding it to your aquarium.


  • Not all types of goldfish are compatible. Check their compatibility before mixing different types of goldfish in your aquarium.
  • Do not put anything sharp in the aquarium. Many types of goldfish have special eyes, which strangely make it difficult for them to see. If they get scared and move fast, they can hurt themselves.
  • Although you will most likely need to mount your aquarium near an electrical outlet, never leave electrical cables dangling over your aquarium. Also, make sure no cables are pulling on the side of the aquarium or its stand.

Popular by topic