Setting up your first Goldfish Tank

If you are thinking of setting up your first goldfish tank, then this article is for you! Goldfish make lovely pets; they come in some stunning colours, shapes and sizes and have fun personalities to go match. They are great for children and adults alike and are one of the "easier" aquarium fish to keep.

Decide on your goldfish tank size and design

Tank size you want for your goldfish is probably one of the most important factors to consider, we would advise at least 40 litres per fish. This does depend on which Goldfish breed you would like, as some get bigger than others, so research is key. For example, the Pearlscale is one of the smaller goldfish reaching around 4” in size, whereas varieties such as the Oranda can reach 8” in size when fully grown. It is important to remember that goldfish are quite speedy growers, so if you are starting with a smaller tank you will need to look at up-sizing within the year. Bigger tanks not only provide more space but they are generally easier to maintain also, larger volumes of water dilute waste so they will need less maintenance than a smaller tank. If you decide to go with a bigger tank you also have more room to allow for more goldfish in the future, it’s always nice to have more than one fish so they can keep each other company.

Design is slightly less important, this is more your preference of style and how your tank will fit in the area designated at home. We would advise against a “fishbowl” design as these tanks are quite out-dated and actually do not provide much swimming space for the fish, they often are also often difficult to attach a tank filtration system too.

Goldfish Aquarium Filtration

A good tank filtration system is a vital piece of equipment for your goldfish tank, the filtration system works at cleaning the tank water of debris and particles as well as harbouring important good bacteria. These good bacteria will break down harmful chemicals such as ammonia and nitrites that are harmful to fish. In regards to your tank filter size, bigger is always better – it will have a larger capacity to hold that good bacteria and will also mean cleaner water, fewer water changes and less filter cleans.

There are three main types of fish tank filters: External, Internal and Hang-on.

  • External Filters are filters that stay situated outside the aquarium (external) and are often intended for larger aquariums that need a large filtration system that are not practical to keep inside the tank.
  • Internal Filters come in many shapes and sizes and are simply put inside the aquarium where they filter in the water and displace back in.
  • The Hang-on Filter is external but without all the pipes work you get on an external, this piece of equipment literally hangs on the edge of the aquarium. Again this is handy if you don’t have much space in the tank for an internal filter. These filters are also good for surface agitation and produce a slower flow rate which is actually better for some fish species including goldfish.

Goldfish Aquarium substrate

The best substrate for goldfish is sand or no-substrate. Gravel substrates are a no-no, this is because stones can get stuck in goldfishes' mouths and can result in choking, this actually quite common this is why we would avoid gravel in a Goldfish tank. Aquarium sand can be sieved and spit back out by your goldfish easily, it also harbours less waste than gravel and we think looks more aesthetically pleasing than a bare bottom tank.

Aquarium plants and ornaments

All tanks look better with some decoration; there are hundreds of fun ornaments you can add that to spruce up the tank. As goldfish are coldwater there are not many live plants you can add, but Anubis plants are hardy can be added. Artificial or plastic plants are also a great addition. These not only make the tank appealing to look at but it also provides enrichment for your fish.

Aquarium Lighting

Lighting is import to represent a daily cycle for sleep/wake. Have a lighting system is also proven to increase colour and vibrancy in livestock. Goldfish don’t need anything too fancy, LEDs are often cheap to run and provide a good spectrum of light to the tank.

Aquarium Temperature

A heater is not an essential piece of equipment for a tropical tank however, some fancy species can benefit from a heater to keep the tank temperature stable. Most goldfish will be happy with temperatures between 15-24 degrees. 

How to start cycling your Goldfish tank

Before adding your goldfish fish to your tank you first need the tank to go through a “cycle” this is very important as if the cycle has not been started or complete before adding fish the water chemistry can be toxic and cause illness and death. To start the cycle you will need to add a source of organic waste or ammonia, the best way to do this is to add in some fish food, this will break down and realise ammonia and nitrite.

The cycle is then started by adding a filtration start or good bacteria to the aquarium, this bacteria will then establish and break down harmful ammonia and nitrite waste in the aquarium.

Cycling your tank is important as fish waste contains ammonia, so once all that good bacteria is established it should then be able to constantly keep ammonia levels down and your fish healthy.

You should test the water often throughout your cycle process using test kits for ammonia and nitrite. Once these levels read very low, you are ready to add your new Goldfish.

What Goldfish to choose?

This is the fun part! There are so many beautiful varieties out there, some of them may have different requirements so make sure you research which one you like. For example, the Ranchu Goldfish need slightly slower water flow as they aren’t the best swimmers and Bubble Eye Goldfish need minimal or smooth surface ornaments for their delicate eyes.

Here are some of our favourite Goldfish types:

Red Cap Oranda Goldfish 

Telescope Eye Goldfish

Red and white Fantail Goldfish

Introducing goldfish into the aquarium for the first time

When you bring your new fish home you will need to correctly acclimate them, this is to reduce shock and stress to the new tank water parameters. Here are some simple steps to acclimating:

  1. Turn the lights off in your tank
  2. Open the bag and allow it to float in the water and match the temperature in the tank
  3. Get a shot glass or a cup and scoop up some tank water and add to the bag
  4. Do this every 15 minutes for 1-2 hours adding more each time
  5. It is best not to pour the water from the pet shop in your tank as it could have harmful treatments or bacteria
  6. Get a bucket and use a net, pour the fish into the net then put in the tank – discarding the water in the bucket
  7. Some fish need longer acclimation than others, so make sure to research what is appropriate for your fish.

Goldfish food

Goldfish are not fussy with their diet; there are many Goldfish flake and pellet brands available that will be happily accepted. Frozen foods such as bloodworm and brine shrimp will also be happily accepted.