Goldfish can be kept as pets. They can live in unheated aquariums and some can live in unheated ponds. Goldfish are quite messy and can grow very large. They need a large aquarium and a good filter. If you want to keep several fish, we recommend looking at temperate or tropical species instead as most don’t grow as large. While some species are great options for beginners, there are others that need more specialist care. It important to choose the right type of fish to suit your experience and lifestyle. 

There are lots of different goldfish varieties. Some of which are better kept outdoors in ponds and others which can be kept indoors. Goldfish are the most well known coldwater species.  

Here are some examples of common types of goldfish 

Standard (single tail) goldfish: Goldfish, Comets, Shubunkins. These goldfish typically grow to around 25-30cm and should ideally be kept in ponds.

Fancy goldfish (not suitable for ponds): Black moor and Oranddas. These goldfish typically grow to around 14cm and should be kept in tanks with a capacity of 60 litres or above, depending on how many you want to keep. A 60L tank is suitable for 2 x fancy goldfish, additional fish will require a higher litreage.

Goldfish prefer to be kept with other goldfish. It is not advised that single-tailed goldfish are kept with fancy goldfish because single-tailed one’s swim faster than the fancies and they often out-compete them for food. In some cases, there are reports of boisterous goldfish fin-nipping the slower swimming fancy varieties. 

Our in-store colleagues can give you’re an idea of how many fish your aquarium maybe be able to hold. If you want single-tailed goldfish, it may be worth considering whether a pond would be better.  

Your beautiful little fish may look tiny at first but a lot of coldwater fish will grow much bigger. An overcrowded aquarium can be stressful for fish and could lead to illness. 

An aquarium of at least 60 litres is a starter size for small goldfish but will need upgrading as they grow. The more fish you want to have the bigger the aquarium will need to be. If you want single-tailed goldfish it may be worth considering whether a pond would be better in the long run.

If you’re caring for coldwater fish, you might want to browse the range of coldwater fish tanks and cabinets at Pets at Home to find one that suits both your space and your fish’s needs.

While goldfish don’t need an aquarium heater, you do still need to invest in some specialist equipment for them. 

You’ll need: 

A suitable glass aquarium (at least 60 litres)

A filter & compatible filter media*

Aquarium lighting*

Fish safe gravel or sand

Aquarium decorations and/or live plants

Tap water conditioner/dechlorinator and filter boost

Water testing kits (ideally ammonia, nitrite, nitrate, pH)

Gravel cleaner/siphon cleaning device (recommended)

Bucket for water changes

Algae pad or magnet for cleaning

*May be included in branded aquarium sets but can be purchased separately.

Decorations make your aquarium look extra special, but they benefit your fish too! Decorations that give your fish somewhere to hide can help your fish feel safe. Look out for decorations that your fish can swim into and conceal themselves. 

Coldwater fish tend to do best at consistent room temperatures. While you won’t necessarily need a heater, you’ll want to keep your aquarium away from radiators, windows and draughts. It is not recommended to keep goldfish with temperate or tropical species of fish. Goldfish are a very adaptable species and through human introductions are now found in the wild on every continent except Antarctica. As they are so adaptable, they can affect native ecosystems. It is important to never release goldfish into the wild. They can tolerate a wide range of environmental conditions. It is suggested that you maintain the temperature between 4-25°C   

Your fish may be a bit nervous and hide for a while, let them settle down for a few hours before feeding them. There are a number of fish foods available in flakes or sinking pellets. Flaked food is suitable for most fish. Sinking pellets are ideal for your Orandas or fancy goldfish. Feed your fish once or twice a day, offering just enough food so that it is eaten within 2 minutes. Start with a small amount and then add a little more if it is eaten quickly. Too much food will pollute the water so make sure any leftover food is scooped from the tank after feeding.  

For a range of high-quality options tailored specifically to goldfish, you can explore the selection of goldfish food at Pets at Home.

A healthy tank for healthier fish: When looking after your fish, little and often is the best practice. Your cleaning plan will depend on the type of tank you have and also what species of fish you have living in.

As a general rule you should aim for the following:
Daily: Check the filter is working correctly.
Weekly: Clean algae from the glass. Carry out a water change of between 10% and 30% of the tank's volume, dependent on how many fish you have in your tank. Clean filter parts & filter media thoroughly in tank water, never clean the media with tap water as this will kill beneficial bacteria. Replace as recommended by the manufacturer. For aquariums up to 68 litres it is recommend that the filter cartridge is changed every 28 days. Replacement cartridge packs available (sold separately).

Our fish health and tank cleaning range includes water treatments, cleaning tools, and other essentials to make the job easy.

Air pumps are a great addition to your set up, they help to circulate water around your tank, allowing CO2 to be released from the waters surface and oxygenating your aquarium to help fish and plant life thrive. Not only are they ideal for the health of your fish and your aquarium, they are perfect for adding depth and creating a decorative effect.