Why Are Goldfish So Hard to Keep Alive? (Full Explanation and Solution)


It’s hard to believe that a goldfish can live for about 10 to 15 years. However, only some make it that far for several reasons. Let’s find out why goldfish are so hard to keep alive.

Keeping a goldfish in a small tank and letting wastepoopbuild up are the two main reasons it dies too soon. When the ammonia levels accumulate to dangerous levels inside a tank, they kill your goldfish.

It’s so disheartening to know that many goldfish kept as pets tend to die due to poor maintenance. But thanks to the following tips, you and your little one can keep your goldfish alive and happy for many years.

What Causes Goldfish to Die Early?

Besides the accumulation of waste in the fish tank and keeping the fish in a small tank, several reasons can lead to the early demise of your goldfish. Let’s dive deeper into the reasons goldfish are so hard to keep alive:

1. Introducing the Goldfish into a Brand-New Tank

Don’t make the mistake of buying everything at once, setting up the tank, and introducing the goldfish once it’s completed. Goldfish should live in a tank that mimics their natural environment

The right environment for goldfish to thrive has bacteria that break down the waste products inside the water to lower the water’s toxic levels.

How to Grow Bacteria for a Fish Tank

You can drop a piece of used filter paper into a new filter box to introduce beneficial bacteria to the new tank. You can also grow bacteria by adding fish food to an empty tank to release ammonia for bacterial growth. Adding water from an established tank or using an aquarium starter kit is also an easy way of growing beneficial bacteria for a goldfish tank.

Give the aquarium enough time to develop bacteria that break down the fish’s waste and any decaying matter inside the tank. Establishing the bacteria colony can take about 4–6 weeks. Ensure that the water inside the tank contains no chlorine because this chemical won’t allow the bacteria to develop.

2. Keeping a Goldfish in a Small Tank or Bowl

Keeping goldfish in a small tank will lead to their early demise. A small tank or bowl doesn’t give the goldfish enough space, oxygen, or clean water to live long.

What size aquarium does a single goldfish need? A single goldfish requires a 10-gallon tank. Yes, you read that right! That goldfish the size of your finger at home in a bowl requires a big aquarium.

A fish tank this size is not only easy to set up and maintain, but it also allows the goldfish to reach their full growth potential.

A small tank or bowl prevents a goldfish from growing because fish release pheromones and hormones that, if left unchecked, can stunt their development.

Depending on your chosen species, goldfish can grow to a maximum length of 6 inches, while others grow to about 14 inches.

3. Buying the Wrong Fish

When buying a goldfish, it’s essential to know that some fish are hardier and easier to maintain than others.

A goldfish from a different temperature and climate than the one you have will be more difficult to keep alive because it will require care you may not have.

The first thing that you need to do is prepare the water to match the goldfish’s demands.

You should remember that goldfish are tropical fish and thrive in cold water. Keeping them in warm water will make your goldfish vulnerable to infections and diseases that will shorten their lives.

The following table is a breakdown of the common goldfish kept as pets, their size, and tank requirements:

NameSize (Fully Grown in inches)Aquarium Size (Gallons)Temperature Range
Celestial Eye Goldfish4 to 62068 to 78°F
Bubble Eye Goldfish4 to 62068 to 78°F
Pompom Goldfish4 to 62068 to 78°F
Telescope Goldfish, Dragon Eye Goldfish, Black, Red and Panda Moor Goldfish7 to 92068 to 78°F
Pearlscale Goldfish4 to 62065 to 72°F
Peacock Goldfish8 to 1020 to 3065 to 78°F
Oranda Goldfish2 to 42068 to 78°F
Butterfly Tail Goldfish7 to 82070 to 80°F
Ryukin Goldfish6 to 1020 to 3065 to 78°F
Lionhead Goldfish5 to 815 to 2065 to 78°F
Nymph Goldfish10 to 122060 to 80°F
Veiltail Goldfish7 to 815 to 2070 to 80°F
Ranchu5 to 815 to 2065 to 78°F
Shubunkin10 to 1210 to 1560 to 80°F
Fancy Fantail Goldfish6 to 82070 to 80°F
Tosakin Goldfish4 to 82065 to 78°F
Watonai Goldfish10 to 123060 to 78°F
Mackerel Tailed Goldfish8 to 102060 to 80°F
Comet Goldfish10 to 123060 to 80°F
Fantail Goldfish6 to 82070 to 80°F
Common Goldfish10 to 142060 to 80°F

4. Using Hot Water or Commercial Cleaners to Wash the Tank Filter

This is a common mistake among many first-time goldfish owners. However, these two practices should be avoided because they kill the essential bacteria that keep the tank in good condition.

Clean the aquarium filter using room-temperature water, but don’t remove all the dirt before placing it again in the tank. The dirt is critical because it also contains good bacteria for your goldfish.

5. Overfeeding Your Goldfish

Giving your goldfish too much food contaminates the water, and the goldfish will die if the water gets too murky.

How much food should a goldfish eat? 

A goldfish should only eat 2 or 3 times a day the amount of food that it can eat for 2 minutes. The food should not exceed the size of its eye.

6. Mixing the Goldfish with Other Incompatible Fish

Goldfish are freshwater fish that don’t do well with other similar fish. Your goldfish might not suffer, but the other fish will because they tend to eat other smaller fish that fits in their mouth.

7. Overcrowding the Aquarium

A goldfish needs enough space to stay healthy, but many owners overcrowd the tank, which causes the untimely demise of their pet fish. An overcrowded tank lowers the water quality, which is vital for the goldfish’s survival. Remember that a 10-gallon tank only supports one goldfish.

8. Buying Unhealthy Fish

An unhealthy fish will not do well even in an excellent aquarium. Do not buy goldfish showing signs of illness, such as weakness and stunted growth. Signs of illness that you should look out for when purchasing a goldfish include:

  • Ragged fins might be a sign of fin rot
  • Sores or ulcerations on the goldfish’s body
  • Lice that affect the fins, gills, and eyes
  • Bloated belly and fins sticking out is a sign of a severe condition known as dropsy
  • Swollen eyes can be a sign of pop eye
  • Unusual goldfish behavior like poor swimming, rubbing against the tank and items inside the tank
  • Lethargy
  • Poor appetite
  • Breathing difficulties

How to Keep Your Goldfish Alive for Years

  • Test the water quality at least once a week using an ammonia, nitrate, and nitrite testing kit. Remember to buy a kit that reads the aquarium’s pH levels.
  • Maintain ammonia levels at 0 ppm because high levels harm your fish’s health. A positive ammonia reading should trigger an immediate water change.
  • Keep the nitrite levels at 0 ppm and the nitrate below 20 ppm. Nitrites are converted into nitrates inside the tank but are dangerous if not kept in check. Even during cycling, don’t allow the nitrite levels to exceed 0.75 ppm. Also, the nitrate levels should be between 5 and 20 ppm. If your test kit finds nitrites in the water, change the water and adjust the filtration system. Nitrates are not harmful when kept at low levels; a partial change reduces them even further.
  • Keep the pH levels between 7.2 and 7.6. You can contact a water specialist in your area if you need help adjusting the pH levels of your goldfish tank.
  • Feed your goldfish a nutritious diet developed for the specific type of goldfish you have. Flaked fish food and pellets are suitable for goldfish and friendly to the tank. However, don’t overfeed your fish.
  • Watch out for any sign of illness and contact a vet if you diagnose any sign of an infection or sickness.
  • Provide a conducive living environment for your goldfish by decorating the tank. However, use something other than wood, which might turn mushy and dirty the water. Don’t add any materials laced with chemicals or ones that may affect the pH levels inside the tank, and avoid placing sharp objects inside the tank.
  • Only add resilient natural plants inside a goldfish’s tank.
  • Add a proper filtration system that’s ideal for the tank you choose.
  • Add clean, balanced water that doesn’t have chlorine and is slightly alkaline (pH of 7.2 to 7.6).
  • Place the tank on a flat, steady surface away from windows or direct sunlight.
  • Maintain the water temperature levels between 60 0F and 72 0F.
  • Cycle the water once a month to ensure the growth of healthy bacteria.
  • Change part of the water once a week.

About Daniel Ladet

Meet Dan, an avid nature enthusiast, and animal lover who spends his free time exploring the great outdoors with his furry friends. Whether he's penning a novel or a blog post, Dan's passion for nature and pets infuses every word he writes, transporting readers to a world of wonder and adventure."

View all posts by Daniel Ladet →

Leave a Reply

Your email address will not be published. Required fields are marked *