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What Happens if You Put Goldfish in a Pond?

Perhaps you have goldfish in an aquarium and are now thinking about moving them to an outdoor pond. Though this process is entirely possible, especially if you live in a warmer climate, it can be challenging with regards to how and why it should be done. Right now, you may be wondering how it affects the fish overall? Well, I have the answer for you below:

If you move your goldfish from a tank into a pond, it’ll allow them more freedom and space to swim and explore. It’ll also provide them with a more natural lifestyle. This can help goldfish live a longer, healthier life.  That said, it can also be dangerous for them if you have larger, more aggressive fish in the pond as well or if the water parameters are not conducive to that of their natural habitat.

Now that you know there are both pros and cons to keeping goldfish in a pond, let’s explore this topic further. In this article, I’ll explain how big goldfish can get in a pond, whether fry can survive, and what the water conditions should be to ensure a successful rehoming. I’ll also discuss if they can live outdoors in the winter, if they need to be fed, and what their greatest threat is.

If your interest in now piqued and you’re ready to learn more about goldfish and keeping them in an outdoor pond, then let’s get to it!

Can Goldfish Survive in a Pond without a Pump?

Goldfish have a far better change of surviving in a pond with a pump and a good filtration system. A well-aerated aquatic environment will keep the water cleaner and safer for fish, thus promoting health and longevity. If kept in a pond without a pond, goldfish will likely only live a week or two as opposed to the average 10 to 15-year lifespan.

How Big will a Goldfish Get in a Pond?

Goldfish will often stop growing to ‘fit’ their aquatic surroundings. When kept in a small aquarium, they rarely exceed 6-inches in length. In a pond, however, with plenty of space to swim and explore, they can grow twice as big (or more) and live years longer! While they’re generally tolerant of a variety of water conditions (hard, soft, acid or alkaline), they can’t survive in a high-ammonia, low-oxygen environment.

How Fast Do Goldfish Grow in a Pond?

In a pond with the ‘perfect’ water conditions, goldfish can grow rapidly (up to 50% faster) within the first few weeks of hatching. Growth rates for baby goldfish are mainly dependent upon water conditions and food quality. The depth of the pond shouldn’t be more than 4 feet (120 centimetres) with a temperature of 70 to 75 degrees Fahrenheit – or 21 to 24 degrees Celsius and a pH level of 7 to 8.

Will Baby Goldfish Survive in a Pond?

For baby goldfish to survive in a pond, it must be set-up properly. It should contain at least 30 gallons of water per fish and have live plants as well as a filter to generate water movement and provide much-needed oxygen. It’s likely that you’ll need to ‘cull’ the pond if you have an abundance of adult goldfish – meaning you’ll have to either sell or give away the ‘undesirable’ ones to make room for the fry.

Can Goldfish Survive in a Pond without Being Fed?

Since goldfish are foragers in constant search of food, the common goldfish can live in a pond without being fed in the winter months – provided that is, that there are organisms present to feed on! If you have live plants growing in the pond, then they’ll likely nibble on those as well as the algae that often coats the pond liner.

How Deep Does My Goldfish Pond Need to Be?

A goldfish pond should be at least 4 feet deep to prevent excess water from evaporating and to keep predators at bay. In colder climates, you may need a deeper pond (up to 20 feet deep), depending on where you live. Investing in an Aquascape Pond De-Icer Heater, available online through Amazon, will ensure your fish stay safe during the winter.

What Kills Goldfish in a Pond?

There are many factors that can lead to goldfish death in a pond. These include disease, physical injury, parasite infestation, predation, old age, suffocation, starvation, stress, severe weather, and water pollution. If you notice a few dead goldfish floating on the surface on your pond, you may to investigate further to determine the underlying cause.

Do Goldfish Eat Algae in a Pond?

As mentioned above, goldfish will indeed eat algae that grows naturally in most aquatic environments, even a man-made pond. Though they eat it, that doesn’t mean it’s good for them. While algae can sustain a goldfish for a while (during the winter months when feeding isn’t possible, for example), it contains very little in the way of essential nutrients.

How Do You Maintain an Outdoor Goldfish Pond?

To properly maintain an outdoor goldfish pond, you must do the following:

  1. Install a filtration system and an air pump.
  2. Test the water every 2 or 3 days for nitrates.
  3. Ensure you have at least 3 to 4 square feet of water space per fish.
  4. Add live plants – enough to cover at least 75% of the pond surface.
  5. Do not use algicide, as algae is a typical food source for goldfish.
  6. Keep the temperature of the water between 65 and 85-degrees Fahrenheit (around 20 to 30 degrees Celsius).
  7. Skim the surface of the water to remove any leaves and/or debris from the pond.
  8. Feed brine shrimp to goldfish twice a day in the summer – in the winter, they’ll survive on the plants and algae living in the water.
  9. Fertilize the plants in the pond regularly, in accordance with the guidelines recommended for each plant type.
  10. Top up the water in the pond occasionally in the summer to account for loss caused by evaporation.
  11. Use dechlorinating tablets (according to the manufacturer’s instructions) regularly to keep the water safe for goldfish.
  12. In the winter, turn off the pond’s filtration system – goldfish will often hibernate near the bottom for part of the season, so don’t add any food to the water at this time.

Is it Illegal to Put Goldfish in a Pond?

It’s definitely illegal in most states and/or provinces in North America to release goldfish into a local pond. The reason being that they can overpopulate and thus overcome the native freshwater fish in the area. This ultimately affects the water’s ecological balance by upsetting the food chain and encouraging the spread of other invasive species.

On the other hand, it’s absolutely legal to put goldfish in a pond on your own property, provided it’s contained and doesn’t connect to any outgoing waterways. The most important thing to keep in mind is not to overstock the pond. This will lead to an overabundance of stunted goldfish that won’t live near as long as they could.

Can You Put Goldfish in a Lake?

Freshwater lakes and slow-moving streams are the natural habitat for goldfish. However, if released into a lake that’s not native to the species, goldfish can grow to massive size (15 inches or 40 centimetres in length) and seriously alter the biodiversity of that aquatic environment. Therefore, you should never release them (or any invasive species, for that matter) into your local lake.


To conclude, it’s possible to move your goldfish from an indoor aquarium to an outdoor pond. This will provide them with a lifestyle similar to that in nature and allow them to grow to full maturity. The downside, however, is that if you have other larger fish in the pond as well, they could bully or even eat the goldfish! The water conditions must be ‘just right’ to ensure the best possible changes of survival.

I trust you’ve found this article to be useful. Thanks for reading and good luck with your goldfish pond!

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