Caring for a goldfish - how to maintain a healthy goldfish

Considered as the third most popular pets after cats and dogs, caring for a goldfish requires effort. Make no mistake, looking after goldfish is not as easy as filling a bowl with water and leaving them to it. While it is not rocket science either, you just need the right tank setup and the patience to learn.

Goldfish are a freshwater fish in the carp family. Also known as Carassius auratus. ‘Carassius’ refers to the fish’s genus (a group of animals including closely related species), and ‘auratus’ means ‘gold’ or ‘gilded’.

Not all goldfish are ‘gold’ in colour and comes in various shades. The Black Moor goldfish has a dark, velvety body.

From left: The Shubunkin fancy gold fish has a rounder body and protruding eyes. | Comets are a variety of common goldfish.

fancy goldfish versus common goldfish

There are many different shapes, sizes, colors, and types of goldfish. Generally, these can be divided into ‘slim-bodied’ types – such as Common goldfish, Comets and Shubunkins are the rounder-bodied ‘fancy’ types.

feeding & nutrition

Goldfish will continue eating as long as there is food available. Unlike humans, They do not have stomachs, so goldfish never get “full”. It is unlikely that goldfish are underfed but overfeeding them is very easy. Do feed your goldfish a maximum of three times daily at a measured amount each time.

Goldfish food will likely be in one of these forms:

  • Flakes
  • Sinking pellets
  • Live foods include brine shrimp, tubifex worms, 
  • Freeze dried live foods

Flakes are popular and a convenient choice of feed.  However, the goldfish may swallow air when eating flakes or floating pellets off the surface of the water, which can cause digestion problems. Also flakes can lose some of their nutritional value after the tub is opened and the flakes are exposed to air. Pellets on the other hand retain their nutritional value better than flakes do.


In caring for a goldfish, the bigger the house, the better. Most importantly, the bowl or tank has enough room for the goldfish to grow. Common goldfish can easily reach 10 inches and fancy goldfish regularly reach 8 inches in length.

Pure Goldfish recommends 1/2 gallon of water for every fish measuring three inches and under or one gallon per goldfish as it gives them more swimming room. The smallest tank for a goldfish is 20 gallons.

Never keep a goldfish in unfiltered water!. They will soon die from disease and water pollution.


Filtration is a must in caring for a goldfish to help it stay alive, or do daily water changes. Goldfish eat a lot and produce too much waste, which can turn the water toxic.

Without filtration. daily water changes is stressful for a goldfish. Often most owners make the mistake of letting the daily water change slide upon seeing that the goldfish seem healthy. While the goldfish may seem healthy, it will soon die from ammonia or nitrite poisoning and will be prone to disease.

Consider an ideal filter that turns over around 10 times the volume of the tank per hour. Always remove any excess food left uneaten.

Even with a filter, the water can quickly become toxic to a goldfish. This happens when the filter is too weak, the tank is too small, rotting uneaten food in the tank, or insufficient water changes.

No goldfish can survive in an unfiltered bowl or tank. While some goldfish can live a few years under such circumstances, their normal lifespan can be 30 years or more.

recent articles on petreview

our preferred partners

The Best Food For Fussy Dogs

Picking food for fussy dogs can be frustrating. The first step is to ensure you are feeding your dog a complete and balanced diet. Generally speaking, smaller dogs tend to be pickier eaters than larger breeds. It is helpful to....

Read More


i'm adopted!

Persian Cat Found At Mei Ling Street

Abandoned in Mei Ling Street for a while, a rescuer has done her due diligence to track her owner and see if she is a lost cat since the cat pop-up out quite suddenly. No one has come forward to....

Read More

Adopt A Cat – New Mother To 3 Kittens

Adopt a female tabby, she recently gave birth to three kittens. Found at Kaki Bukit, a rescuer took her home upon seeing some discharge. The cat gave birth the next day to three kittens. As the kittens are bigger than....

Read More

upcoming events

No posts found!