I was wondering whether the age old tradition of feeding bread to fish (and goldfish specifically) was actually a safe one, so I decided to do a bit of research on the subject.
That led to a lot of research, which led to this article.
Goldfish should not eat bread, as bread can be harmful to goldfish. Bread can cause digestive issues and conditions such as swim bladder disease. For this reason, most grains (not just bread) should be avoided or pre-soaked when feeding goldfish.
Goldfish can eat a lot of things safely in the short term. It’s not always easy for you to tell what they can safely eat long term, however.
In this article, I’m going to cover the one grain that actually is safe, which food group should make up most of your goldfish’s snacks, and which foods are safe in moderation. I’m also going to cover which foods are safe in the short term but can lead to long term health issues.
What Human Foods Can Goldfish Eat?
Grains
The first category of food that I am reviewing is grains.
In the human world, there is quite a a large contention about how healthy grains may or may not be for humans.
In the fish world, this debate is also going on. For example, anglers have been feeding fish bread crumbs for decades without any real problem, but a lot of people are coming out now saying that it’s actually unhealthy for the fish.
And this seems to be the case for most of the grains on our list. In general, fish should evidently not be fed grains.
There is one grain, however, that appears to be quite healthy for your goldfish. Read on to find out which one.
Can Goldfish Eat Bread?
Caution!
If your goldfish has eaten a bit of bread, you don’t necessarily need to worry. It’s not directly poisonous to them. (In fact, there are references to feeding fish bread going back hundreds of years.) This does not mean, however, that you should feed goldfish bread or bread crumbs. In fact, it should generally be avoided.
The reason for this is that the bread can swell up in your goldfish’s stomach, causing constipation and other health problems. (This could lead to problems that you’ll have to fix later.)
Plus, bread just isn’t that healthy for goldfish. Especially white bread, which the UK banned as fish bait in 2011.
We all probably have fond memories of feeding bread to fish and ducks when we were younger. Unfortunately, they should stay memories.
There are plenty of healthier options, so you should skip this one.
Can Goldfish Eat Crackers?
Caution!
In general, goldfish should not be given crackers to eat. In addition to being unhealthy, crackers could swell in your goldfish’s intestines, causing constipation or more serious blockages. That said, crackers are unlikely to kill your goldfish if it does eat one.
Crackers share all of the same problems with bread above.
What’s more, since goldfish are prone to overeating (and fancy goldfish are especially prone to constipation and blockages already), they are more likely to run into these sorts of problems as it is.
The verdict? Do not feed crackers to your goldfish.
Can Goldfish Eat Rice?
In Moderation
Can goldfish eat rice? The short answer is yes. They don’t get any nutritional benefits from it, but they can eat it. (Some commercial fish foods use rice as a filler.) If you feed your goldfish rice, make sure it is properly cooked so that it isn’t likely to expand inside them once they eat it.
My recommendation, however, would be that you avoid feeding your goldfish rice.
It’s not going to harm them, and you don’t have to worry if they eat a few grains, but it also replaces the opportunity to feed your goldfish a healthier snack (such as leafy greens or peas).
In addition, goldfish are already prone to overeating. I’ve talked previously about goldfish being able to get all the nutrition they need from the amount of food they can eat in 30 seconds. (And how the common rule of thumb that you feed them 2-3 times per day for 2-3 minutes each time is overfeeding.)
Feeding rice on top of this is unnecessary and may lead to fat goldfish and excess ammonia in your tank.
The verdict on rice? As long as you don’t feed too much, rice is fine. I recommend you skip it in favor of a healthier treat, however.
Can Goldfish Eat Oatmeal?
Go for it!
Can goldfish eat oatmeal? Absolutely. While it shouldn’t be their primary food, goldfish appear to like oatmeal, and it seems to be quite healthy for them as a snack. Breeders commonly feed soaked or cooked oatmeal to their goldfish as well.
It’s important to note that – while large goldfish can eat raw oatmeal flakes – smaller goldfish should be given oatmeal that has been soaked or cooked the same way you would cook oatmeal for yourself (without any additives). You should also give young fish smaller pieces to avoid potential issues with intestinal blockages.
While you’re cooking it, you can also add powdered shrimp or blood worm for flavoring, though your goldfish will be happy to eat it without.
Advice has been given in publications going back at least as far as 1917 to let young fish have as much as they can eat during the day, but to clean it out at night. This was thought to encourage the development of a short, round body shape. At 2 years, you would start giving much less oatmeal. (Though it is still quite healthy for them.)
I don’t know if this advice is still considered good or not (especially if they’re in an undersized tank or bowl where waste could be a problem), but I would still consider oatmeal to be a healthy treat in the right amounts.
The verdict is, therefore, that oatmeal is safe and healthy for your goldfish.
Can Goldfish Eat Cereal?
Best Avoided!
Because grains are generally not advisable to give goldfish to begin with, and because of the extra ingredients in cereal, you should avoid feeding cereal to your goldfish. Small amounts may not kill it, but you should opt to feed goldfish food or leafy greens instead.
There is some anecdotal evidence to suggest that some of the ingredients commonly present in cereal – such as chocolate or marshmallow – may be harmful to some species of fish (potentially including goldfish).
In addition, since they’re grains, they’re likely to expand a bit once ingested, which may also cause some problems with constipation.
Have goldfish that have eaten cereal?
It probably won’t kill your goldfish (in small amounts, at least). You may want to follow up by feeding them some peas, however.
The verdict? Best not to feed cereal to your goldfish.
Vegetables
When it comes to vegetables, the answer generally seems to be a solid yes.
Out of the human food groups, vegetables seem to be the ones that you can most feed to your goldfish (and feed with the least amount of worry).
That doesn’t mean that all vegetables are safe however, or that they’re safe in all amounts.
Read on to find out specifically which ones you need to feed in moderation only and which leafy green you should avoid.
Can Goldfish Eat Carrots?
Go for it!
Can you feed your goldfish carrots? Absolutely. Carrots can be a healthy treat for goldfish. They also have the added benefit of enhancing your goldfish’s color. Carrots are commonly included in many homemade goldfish foods and commercially available koi foods. Carrots should be boiled before feeding.
Carrots are one of the first foods on our list that get a definite endorsement for feeding to your goldfish.
Because of the carotenoids in carrots, carrots are said to be able to enhance the color of your goldfish. This is because goldfish get the compounds that produce their orange color from their diet, rather than creating it themselves.
(You can also enhance the color of your goldfish by providing them better lighting – or direct sunlight – and making sure the quality of their water is good.)
There is one thing you should know before feeding carrots, however:
If you just throw a whole carrot into your goldfish’s tank, they’ll have a pretty hard time eating it.
Instead, what you should do is cook it for a few minutes – until soft – and then finely chop it before feeding.
This will produce small, soft pieces that are easily eaten by your fish.
The verdict? Cooked, finely chopped carrots are a safe food to feed your goldfish.
Can Goldfish Eat Lettuce? (Or Spinach, Kale, and other Leafy Greens?)
Go for it!
Lettuce is definitely safe for goldfish to eat. In fact, it’s encouraged that you feed them leafy greens – including lettuce, turnip greens, and spinach – regularly, as they are naturally used to foraging throughout the day.
The ideal feeding schedule for your goldfish is to feed them what they can eat in 30 seconds each day. (Using, of course, high quality goldfish specific food.)
When followed this will do two things:
- Prevent your goldfish from overeating.
- Cause your goldfish to beg you for food the rest of the day.
Rather than giving in and giving them more food, it’s recommended that you provide them a variety of leafy greens for them to forage on, as they would in their natural habitats.
Some leafy greens you can safely give your goldfish include:
- Lettuce (All varieties including iceburg, arugula, etc)
- Spinach
- Turnip Greens
- Kale
- Radish Leaves
It’s important to note that not all leaves are safe, however. Rhubarb greens, for example, should be avoided.
One thing to note is that your fish might avoid eating leafy greens at first, choosing to beg you for more of their normal food instead.
You should avoid giving in (feeding them extra) and instead get them used to foraging on vegetables throughout the day.
Your goldfish will be much healthier for it.
And since they’ll produce less ammonia than overfed goldfish, everything else in their tank will also be healthier.
Something you can do to make your lettuce easier for your goldfish to eat is to briefly microwave it until it gets wilted. This will make it softer, which will in turn let your goldfish eat it more easily.
The verdict? Lettuce and other leafy greens are not only safe for your goldfish to eat, but are extremely healthy to feed. It’s highly encouraged that you make this food available to your goldfish.
Can Goldfish Eat Peas?
Go for it!
Goldfish can eat peas, as long as the peas have had the skins removed first. Peas can even be used to remedy certain health issues in your goldfish. You may want to briefly cook them to soften them and/or chop them into smaller pieces that your goldfish can eat whole first.
Second only to leafy greens, peas make the top of our list for healthiest vegetable to feed to your goldfish.
They are definitely healthy vegetables. But that’s not the only reason for the high praise this humble vegetable receives.
Peas also have the ability to cure a very serious problem that a lot of goldfish have.
Ever notice your goldfish floating to the top or the bottom of the tank (or swimming on their side, upside down, or straight up and down) without being able to control themselves?
If so, you were seeing something that is commonly known as swim bladder disease.
Rather than being a single disease, swim bladder disease is a blanket term for a number of conditions – most notably constipation.
When your goldfish gets constipated, the food in its intestines can push against the swim bladder. This prevents it from working properly.
When this happens, your fish can go out of control – helplessly swimming upside down or any other number of ways a fish isn’t supposed to swim.
The cure to this strange condition is – of course – peas.
Before you feed peas to your goldfish, you need to remove the skin from the pea. The skin can cause your goldfish to choke.
Once you remove the skin from the pea, chop or smash it into smaller pieces before feeding.
The verdict? Peas are a safe and healthy treat for your goldfish.
Can Goldfish Eat Cucumbers?
Go for it!
While cucumbers aren’t as healthy as spinach, peas, or other nutrient dense vegetables, goldfish can definitely eat cucumbers. Since goldfish like foraging throughout the day, the occasional cucumber can be a healthy addition to your fish’s diet (though should not replace their actual food).
Cucumbers are definitely not the healthiest option on this list, but they are certainly safe for your goldfish to eat.
There are a few things you want to do before feeding cucumbers to your goldfish:
- Remove the skin (and seeds if your goldfish don’t like them)
- Blanch or microwave it to make it soft and mushy.
- Cut it into small pieces for feeding or clip it to the side of the tank to give them an easier time of eating it.
The verdict? Cucumbers are a safe treat for your goldfish.
Can Goldfish Eat Garlic?
In Moderation
Goldfish can certainly eat garlic. In fact, a lot of commercial DIY goldfish food recipes include garlic as an ingredient. In small amounts, it can stimulate the appetite and provide other benefits. Garlic should be fed in moderation, however, as it can potentially be toxic in large amounts.
High enough doses of garlic can be toxic, even to humans.
That having been said, garlic is fine to add in small amounts to other foods you are feeding your goldfish.
Garlic is commonly added to goldfish specific foods, both commercial and home made. A lot of commercial foods may not have enough garlic in them to actually benefit your goldfish, however, so you may want to add freshly pressed garlic to food or treats you’re providing your fish.
There is some evidence to show that garlic may have the following health benefits for fish:
- Appetite stimulation
- Kills some parasites, including ich
- Kills some varieties of bacteria and other pathogens
For more information on the topic, I recommend you read this article.
The verdict? In moderation, garlic is healthy for your goldfish and may have extra health benefits.
Fruit
Most fruits are safe for goldfish, but they should be given sparingly compared to vegetables. They should also never be given as a replacement for an actual balanced goldfish food.
Can Goldfish Eat Apples?
In Moderation
Goldfish can certainly eat apples without any negative effect on their health. Before you feed the apple to your goldfish, however, you should remove the skin and cut the apple into tiny pieces.
I wouldn’t recommend you feed apples to goldfish in the same quantities you’d feed them some of the vegetables on our list. (This is primarily due to the extra sugar and calories found in apples.)
That doesn’t mean that you can’t feed them apples at all. Apples are fine as an occasional treat.
Like peas, however, the skin should be removed before you feed them apples – because it may cause them to choke.
You may also want to microwave the apple briefly to soften it some, though this isn’t strictly necessary.
The verdict? In moderation, apples are a healthy treat for your goldfish.
Can Goldfish Eat Watermelon?
In Moderation
Watermelon is an excellent treat for your goldfish (on occasion). Watermelon is also one of the treats we recommend you give to your goldfish without breaking down into bite sized pieces. Just remember to remove the seeds first before giving it to them.
While it shouldn’t be given with the same regularity as leafy greens or other healthy vegetables, watermelon is a safe food to give your goldfish.
Since watermelon floats, if you provide it in larger pieces than they can eat in one bite, it can provide them a bit of exercise as well.
Set a piece on top of the water, and they will chase it around the tank until it has been completely eaten.
This can certainly be fun to watch – and is probably good exercise as well.
The verdict is therefore that watermelon is fine to give your goldfish as an occasional treat.
What Animal Foods Can Goldfish Eat?
Unprocessed Food
Can Goldfish Eat Mealworms?
In Moderation
Are mealworms safe for goldfish? Absolutely. Goldfish are omnivores, and mealworms are one of the many bugs that goldfish can safely eat. Unless you’re making homemade goldfish food, however, mealworms should be fed sparingly – to avoid polluting the water water with excess ammonia.
According to the New York Zoological Society, mealworms are one of the types of worms that you can safely feed to your goldfish.
You should avoid feeding them regularly, however, as the excess fat and protein can be harmful to your fish. (See table below for nutritional comparison.) This is not only because of the excess food polluting the water, but also because it may cause fat buildup around your goldfish’s organs.
You should also avoid freeze dried worms in favor of live or frozen ones. If you are using freeze dried worms, you should soak them prior to feeding so that they re-hydrate. (This is to avoid digestion problems that occur due to the food expanding inside of your goldfish’s intestines.)
The verdict is that mealworms are safe for goldfish, but should be used as an occasional treat.
Can Goldfish Eat Wax Worms?
Caution!
Wax worms are not inherently dangerous to goldfish (meaning they can eat wax worms without dying or getting sick), but you should avoid feeding your goldfish wax worms due to their high fat content, which isn’t healthy for your goldfish.
To get an idea of the fat content of wax worms, take a look at the following nutritional breakdown:
| Type of Food | Fat | Protein | Moisture |
| (Northfin) Premium Goldfish Food | 5% | 36% | 9% |
| Wax Worms | 22% | 15% | 61% |
| Mealworms | 12% | 20% | 62% |
| Bloodworms | 1% | 8% | 81% |
As you can see, wax worms are much higher in fat than any of our recommended foods.
Because of this, we highly recommend you skip wax worms when considering what treats to feed your goldfish.
Can Goldfish Eat Bloodworms?
In Moderation
Your goldfish can safely eat bloodworms. Most of the commercially available bloodworms are fly larvae, so this is a type of food that would be readily available in nature for your goldfish to eat. Bloodworms can be high in calories, however, so you should feed in moderation only.
The term “bloodworm” can be used to refer to multiple, unrelated species of worm-like creatures.
Since most of the ones you can buy at the store are the larvae of midge flies, however, this is what I’ll be covering in this section.
Bloodworms themselves are safe to eat and are actually preferred over other types of worm such as the wax worm due to their lower fat content.
To avoid feeding your goldfish too many calories, however, you should reserve bloodworms to being fed once per week or less often.
If you follow these instructions, the verdict is that in moderation, bloodworms are safe for your goldfish.
Can Goldfish Eat Brine Shrimp?
In Moderation
Your goldfish can eat brine shrimp, but you should feed brine shrimp only in moderation. Brine shrimp are high in calories, and if fed too often they can lead to weight gain and excess ammonia production in your fish tank. They are safe for your goldfish to eat in moderation, however.
Brine shrimp fall into the same category as bloodworms (with similar nutritional breakdowns), in that they’re safe to eat and preferrable to some other live foods you can give your goldfish.
They have the added benefit of being able to be purchased as live feeders for your goldfish, which can be a nice treat for your fish.
They are high in calories, however, and when fed in addition to their normal fish food, they can lead to overfeeding.
The verdict is that brine shrimp are a healthy treat for your goldfish when given in moderation.
Can Goldfish Eat Ants?
Sure
Goldfish can safely eat adult ants as well as their larvae and eggs. In nature, goldfish would naturally forage for any insects that fall into the water. If ants are straying close enough to your tank or pond to get eaten by your goldfish, you need not worry. Ants are indeed safe for goldfish to eat.
It is important to note that if you are trying to stop an invasion of ants into your house (or pond) you should pay extra close attention to making sure any chemicals aren’t brought into your fish’s water.
Keep in mind that if you use bait traps, the ant may consume the bait and then fall into your goldfish’s tank, leading to your goldfish consuming the ant poison.
This may or may not have a immediately harmful effect on your goldfish (depending on the type of poison), but it should be avoided as much as possible.
If you are dealing with ants in your house, you should try to find the way they are getting in and seal it off. When dealing with ants outside, you can find their nest and pour a large pot of boiling water on the nest to kill it (if you are concerned enough to do so.)
The verdict, however, is that ants are a safe treat for your goldfish on the occasion that they fall into the water.
Can Goldfish Eat Algae?
Go for it!
Goldfish can safely eat algae as much as they like. Goldfish are natural foragers, meaning they are always looking for something to eat, even if you’ve fed them enough. Algae is a natural outlet for that need to forage and can be healthy for them as well.
If you’ve noticed your goldfish swimming around their pond (or tank), nibbling on algae, you need not worry.
Goldfish are omnivorous fish, and algae is a natural part of their diet.
It actually can compete with the other leafy greens for the top spot on our healthiest foods list, because if they are foraging for algae, they’re not begging for high calorie foods that might make them fat and pollute their water with ammonia.
The verdict, therefore, is that algae is a safe food for your goldfish to eat.
Processed Food
Can Goldfish Eat Tropical Fish Food?
In Moderation
Goldfish can eat tropical fish food, but it’s not advisable to feed them tropical fish food for a long period of time. Tropical fish food will likely be higher in protein and lower in carbs, which can pollute your tank and harm your goldfish in the long run.
Since goldfish are omnivores, they can eat pretty much anything This includes tropical fish food.
Just because they can eat it, however, doesn’t mean they should.
Here are some things to consider:
- Tropical Fish Flakes – Flake foods may cause your goldfish to gulp air. This can contribute to swim bladder disease (and should be avoided).
- Tropical Fish Pellets – These are better than flake foods, but goldfish require a different balance of protein, fat, and carbs than a lot of species of tropical fish. This can cause all sorts of problems if fed as a long term solution.
The verdict on this one is it’s okay if you don’t have any other fish food, but you should replace it with goldfish specific pellets or gel food as soon as possible.
Can Goldfish Eat Betta Food?
Best Avoided!
While goldfish can eat betta food temporarily, you should avoid feeding it to them. Bettas are carnivores, and therefore have different dietary needs compared to omnivores like goldfish – such as increased fat and protein. Feeding your goldfish Betta food long term can cause health issues.
Let’s look at two pellet foods from the same manufacturer:
| Type of Food | Fat | Protein | Moisture |
| (Northfin) Premium Goldfish Food | 5% | 36% | 9% |
| (Northfin) Betta Bits | 16% | 45% | 9% |
You can see that the goldfish food has only 5% fat and 36% protein, and the Betta food has 16% fat and 45% protein.
That’s almost 3x the fat and 25% more protein.
Considering that goldfish have problems digesting protein, this can lead to a whole host of problems.
(Not the least of which being the production of excess ammonia, which will poison all of the fish in the tank.)
The verdict is therefore that Betta food should be avoided.
Can Goldfish Eat Algae Wafers?
In Moderation
Goldfish can safely eat algae wafers. You should avoid feeding these to your goldfish on a regular basis, however, because they are a high calorie food. (And this can lead to overeating – which will cause health problems for your goldfish.)
Compare goldfish food to algae wafers:
| Type of Food | Fat | Protein | Moisture |
| (Northfin) Premium Goldfish Food | 5% | 36% | 9% |
| Algae Wafers | 4% | 33% | 10% |
You can see that – comparing the macronutrients – these are two very similar foods and probably have similar calories.
If you feed your goldfish the correct amount of goldfish food, and then you feed them algae wafers in addition to that, you’ll wind up with them eating too much.
(Plus, the algae wafers are designed for herbivores and might not have everything your omnivorous goldfish needs. That said, they are better than many of the foods on this list.)
The verdict is if your goldfish eats an algae wafer meant for your algae eater, you don’t need to worry. You shouldn’t feed them as a snack, though.
Can Goldfish Eat Shrimp Pellets?
In Moderation
Goldfish can eat shrimp pellets, but shrimp pellets should not make up the majority of their diet. Shrimp pellets are very heavily meat (though they are made for omnivores), and goldfish would have historically had a mostly vegetarian diet (with meat when they could catch it).
I highly recommend you select a food that is specifically formulated for goldfish to feed to your goldfish.
If you have different types of fish in the same tank, where some of the fish will eat shrimp pellets and others will need goldfish food, this might be difficult to manage. Placing the foods in different ends of your tank may help in this case, and if some of the goldfish eat the wrong food, you don’t need to worry.
The verdict is that shrimp pellets are safe for goldfish but shouldn’t make up a large portion of their diet.
Can Goldfish Eat Koi Food?
Go for it!
Goldfish and Koi are related fish with similar dietary needs, so goldfish can eat koi food indefinitely. In fact, most Koi food will say on the packaging that it is also safe to use for Goldfish.
Most of the animal foods I’ve reviewed on this list have had pretty much the same recommendation – eating it in the short term won’t harm them, but don’t feed it to them more than necessary.
Koi food is a break from that pattern.
If you have a good brand of Koi food, feel free to feed it to your goldfish as it’s primary food for as long as you want.
The verdict on Koi food is that it is similar – nutritionally – to goldfish food, and you can swap one out with the other as you want.
Can Goldfish Eat Turtle Food?
In Moderation
Turtle Food such as Reptomin isn’t harmful to goldfish, but it should not be used as a substitute for actual goldfish food. It is generally higher in protein, and it may not have the correct balance of micro-nutrients to keep your goldfish healthy.
Goldfish may love to eat turtle food (and the ingredients used in the two are very similar), but turtle food should be viewed as nutritionally incomplete and thus not suitable for goldfish.
It’s quite high calorie, so you should avoid feeding it as a snack except on a rare occasion.
If your goldfish does get a hold of some turtle food, you probably don’t need to worry too much about its safety, however.
The verdict is still that goldfish shouldn’t be purposefully fed turtle food.
Conclusion
A general rule of thumb that came up during my research is that it’s generally safe to feed vegetables (the lower calorie ones in particular) and to feed fruits in moderation. Other types of food should be viewed with a bit of suspicion.
Some, such as grains, should be generally avoided because they can be harmful, and others, such as animal foods, should be avoided because they are high calorie foods that aren’t suitable to be the primary food for goldfish.
There are, of course, some notable exceptions, but in the absence of solid information otherwise, it may be safe to follow this rule of thumb (and to remember – when in doubt, avoid feeding it).
Wondering about any other foods? Do you have experience feeding one of the foods on this list to your goldfish? Let me know in the comments!
