What Do Goldfish Eat? Learn What To Feed Your Goldfish

What has teeth in his throat instead of his mouth, no stomach at all and yet will eat himself to death, given the chance? If you said a scary sea monster, well you’re close.

But think smaller. Think cuter. Think that friendly little goldfish in your living room.

From their mouth to the – erm – other end, they have a very interesting digestive system that affects how they eat. But what do goldfish eat? and What should you feed them in your home aquarium?

What do goldfish eat written beside a goldfish rummaging in a planted tank
© madhourse / Adobe Stock

Teeth in their throat, eh? Who knew that the common goldfish could be such a fascinating creature? The more you learn about this humble fish, the more you realize that they aren’t actually that “common” after all.

Their unusual characteristics mean you need to approach feeding with a bit more care than with other fish.

Don’t panic though, there’s nothing hard about it. In fact, you might even find that adding a bit of food variety to your fish’s diet makes mealtimes a bit more interesting for you and them, as a little thought and effort on your part adds enjoyment to the hobby of fish keeping.

What do Goldfish Eat in the Wild?

Asking what goldfish eat in the wild is a bit of a trick question as they aren’t a wild species and only exist in home aquariums. However, they are closely related to carp.

In the wild, these omnivores will eat pretty much anything that doesn’t put up a fight and dine on a mix of insects, plants, algae, zooplankton, snails and small crustaceans. This large variety of food gives the fish all the protein and minerals and vitamins that they need.

Dieting on a mix of foods, both plant and animal, ensures they get all the nutrients they need.

If goldfish were wild, with highly comparable nutritional needs and digestive systems as wild carp, it’s safe to say they would eat the same.

So how do we replicate this in an aquarium?

What To Feed Your Goldfish at Home?

For the absolute best you can do for your goldfish, you want to feed them a diet as close as possible to what they would eat in the wild.

But not only matching which foods they eat, you also want to mimic how often they eat, and in what manner.

Should you feed them once per day? 2 times? 3 times? Should you feed them one large lump, or hide bits around the tank for them to rummage and find, grazing slowly perhaps over hours?

First, let’s look at feeding frequency.

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How Much Should I Feed My Goldfish?

To properly care for your goldfish, they need small meals several times a day. If given the chance, they are a grazer. They would not sit down to one large meal and then not eat for hours, they would forage throughout their environment looking for food to graze on slowly, for much of their time throughout a day.

With this in mind, aim to feed your fish 2 to 3 times a day and let him eat for a total of 5 to 6 minutes. That’s around 2 to 3 minutes per feed.

When the time is up, remove any left over food from the tank.

Why? For the following two reasons.

Goldfish Are Opportunistic Eaters

First, goldfish are opportunistic eaters, meaning that when it comes to food, they have less willpower than your uncle at a Thanksgiving dinner.

Your fish will eat and eat and eat and then eat some more. Some people even claim that goldfish will eat until they explode, though it’s more accurate to say that they will eat until their intestines are impacted and the rotting food in their digestive tract leaves them susceptible to death by disease. Which is a whole lot less dramatic, I know.

Either way, it’s important that you don’t overfeed them. To protect your pet, you need to remove the extra food from the tank before he eats too much.

Uneaten Food Becomes Toxic

Second, any food that ends up in the substrate will end up rotting and polluting the water with ammonia, which could end up poisoning your fish.

Removing any uneaten excess from the tank will help keep the water healthier and cleaner.

Do Not Overfeed, Underfeed If Anything

It’s far more dangerous to overfeed a goldfish than it is to underfeed one.

How can you tell if you’ve overfed yours? One telltale sign is a long string of faeces trailing behind your fish as he swims. If they can poop that much, they’ve eaten too much.

If five year old boys are laughing hysterically at the poo strings your goldfish is sporting, you might want to consider scaling back at mealtimes.

Choosing Goldfish Food: Pellets Or Flakes?

A pile of goldfish pellets next to a pile of goldfish flakes on white background
© Depositphotos.com / decius, and Graham P

What should most mealtimes consist of?

The bulk of your goldfish’s diet will be made up of a quality, commercial fish food. Head on over to your favorite pet store and check out the selection available, the variety is astounding!

Most importantly, find a food that is specifically formulated for goldfish.

Compared to other fish, goldfish need a lower protein, higher carb diet, and you’ll want a food that meets these demands. So don’t just buy any old packet that’s made for other fish breeds or marketed as ‘good for all and any.’

The labels on the food canisters should tell you the percentages of protein ipresent.

If kept in cool water (below 60 degrees) they will need about 25 percent protein, while fish swimming in warmer water might do well with a higher amount.

Be careful that the food you choose doesn’t include a lot of cheap, nutritionally empty fillers like corn or soybean which are hard for goldfish to digest and will cloud up the water.

The best course of action is to read reviews and find a well trusted, highly recommended brand known for it’s quality.

Once you’ve decided on a quality fish food brand, you then need to decide whether to purchase pellets or flakes. Opinion is divided over which is better, as there are pros and cons with each choice.

Goldfish Flakes – Pros and Cons

Pros

  • Flakes float on the surface of the water, which makes it far easier for you to remove any uneaten food after a couple minutes.
  • Good for varying your fish’s diet

Cons

  • Flakes contain less roughage than pellets, so they’re harder on a fish’s digestive system
  • When fish eat from the surface, they may swallow air. This leaves the fish susceptible to digestive problems like swim bladder disorders
  • Flakes don’t stay fresh as long so you might end up buying them more often

Goldfish Pellets – Pros and Cons

Pros

  • In the wild they tend to eat at the bottom or the middle of the water, not at the surface. Sinking pellets are a bit more natural in this sense.
  • Pellets stay fresher longer than flakes and so they might be more cost effective in the long run.

Cons

  • It’s much harder to remove any uneaten food because it falls into the substrate.
  • Some pellets are too big for a goldfish you need to find an appropriate size. Fish rummaging through the substrate might accidentally swallow gravel.

If you can’t decide which to use, why not try both?

There is no harm in giving your fish a little bit of variety. In fact, your goldfish will welcome some diversity in their diet. Remember that in the wild, carp eat a wide selection of foods and we want to mimic this.

Having said that, our recommendation is to feed pellets.

This is because ideally, they would do most of their foraging and feeding on the bottom to mid-water and only occasionally feed from the surface.

Supplementing Your Goldfish’s Diet

It’s fun to treat a fish every now and then with other foods. It doesn’t have to be anything fancy, of course. Chef Ramsey isn’t going to be stopping in to check on your presentation or anything.

Add Some Fruit And Vegetables to Your Goldfish’s Diet

Goldfish love to eat shelled peas, boiled veggies such as brocolli, leafy greens, lettuce or boiled corn. Cut up melon slices, grapes, and cucumber.

A veggie clip is a handy tool for keeping the food secure at the bottom of the tank. If you don’t have one though, a small bulldog clip is good to use, with the weight able to keep most fruit and veg from floating to the top.

These fruits and vegetables will give your fish some much needed fibre to keep their digestive systems moving smoothly.

Also add Some Bloodworms, Brine Shrimp or Daphnia

Blood worms, Daphnia and brine shrimp are always a welcome snack. You can purchase these at your pet store or even raise brine shrimp yourself.

Keep in mind though that if you choose to use live foods, there is a small chance that diseases can be passed on to your fish. Using frozen or freeze dried food, though less nutritious, will eliminate this risk.

Consider Adding Edible Plants To The Tank

Another option for supplementing your fish’s diet is to provide some tasty plants.

Plant some in the gravel for your fish to peck at or top your aquarium with a floating plant. Duckweed is a popular choice they love to snack on, but there are many others.

Of course, just like any other pet, they should not be overfed treats! However, including them regularly is an important part of caring for your fish.

Some Top Tips for Feeding Your Goldfish

Feed your goldfish smaller amounts, 2 or 3 times per day. Feeding them just once doesn’t fulfil their natural inclination to eat little and often.

Try to feed them at the same time every day. Like all animals, goldfish are creatures of habit and will thrive best with routine. In time, they even learn to know when dinner time is and will come to the surface for feeding when you approach the tank.

After just 10 or so minutes of feeding your fish, remove any uneaten food. Once they’ve had their fill, if there’s plenty left over it will only serve to pollute your tank when it starts to rot, or gets buried in the gravel or sand over time.

If your tanks size is sufficient yet when you test your water parameters it show pollution quickly, it’s likely you are overfeeding your fish. Goldfish are prolific eaters, and hand in hand (or fin in fin?) with this comes being prolific waste producers. The more you feed, the more waste they generate. They only need food about the size of their eyeball, 2 or 3 times per day and no more!

Only feed treats twice a week. High protein treats are a necessity for a balanced diet and to keep things interesting for your fish, but if fed too regularly can actually be damaging to your fishes health, particularly the liver. High protein, fatty foods should be just that, an occasional treat, not a daily occurrence.

Final Thoughts

As a staple daily food, we recommend sinking pellets with the occasional feeding of flakes for variety.

On top of this, we recommend occasional bloodworms and brine shrimp. We recommend dried or frozen if you aren’t going to grow your own as the risk of parasites and bacteria is unfortunately quite high…unless you find a good, reliable source.

Finally, add the odd edible plant or occasional piece of fruit or veg to their diet, to add the final touches to mimicking their natural diet.

This variety of food provides your fish with the full range of vitamins and minerals that they would find in their natural habitat, and with just this little bit of effort, you can ensure your goldfish lives a long and healthy life.

Happy fish keeping!

Wendy Kathryn

Hi, I'm Wendy, the owner and creator of this website, an experienced fish keeper and avid student of the art since 2010. My aim is to help beginners avoid the many possible mistakes when getting started in this wonderful hobby.

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