Goldfish are medium-maintenance fish preferred by many pet owners. The goldfish are not choosy or picky eaters. They eat almost any food you feed them in the fish tank. But does it mean they will eat tropical fish food as well?
It’s not uncommon for fish keepers to wonder if they can feed the same food to goldfish and tropical fish. It is convenient and cost-effective, after all. But, how safe is it for a goldfish to eat tropical fish food? What are the possible consequences?
Yes, goldfish can eat tropical fish food. However, it should not be their only diet. Goldfish are omnivorous. They require a varied diet with high nutrients to grow healthy and strong. Feeding goldfish only tropical food will make them weak and cause adverse effects.
Let’s find out more about what happens when goldfish eat tropical fish food and what to feed your pet goldfish to ensure its long lifespan.
Can I Feed Tropical Fish Food to a Goldfish?
Even though you can feed tropical fish flakes to your goldfish, this alone won’t be enough for goldfish. Goldfish food has plant-based nutrients, while tropical fish food has more protein content.
Fish keepers like to maintain a variety of fish in their aquariums. The goldfish is one of the most common pets people have. However, a goldfish is a freshwater fish, different from tropical fish like guppies.
This means you should buy two types of fish foods. However, with so many options in pet stores (and many of them are confusing), it can be difficult to choose the right fish food for your pets.
Your goldfish needs diverse feed to have a well-balanced diet. Without the recommended feeding, the goldfish may display signs of slow growth and dull colors and die much earlier than its intended lifespan.

How are Goldfish and the Tropical Fish Different?
While it may seem like tropical fish and goldfish have similarities, these two are different in many ways. The food they require is also different, even if a few items are common.
Tropical fishes are species found in freshwater and saltwater from the tropics (Asia and Florida, US). These are easy to raise, feed, and breed at home or on farms. Tropical fish need 30% protein if they are herbivorous and a minimum of 45% protein if they are carnivorous.
Goldfish are freshwater fishes but not tropical. These fish need a different water temperature and diet. They also require extra space to swim and a quality filter system (as they generate a lot of waste). Goldfish prefer a mixed diet with plant-based foods and animal-based live food.
A study shows that an ideal diet for goldfish consists of 29% protein, 13% lipids, and 9.7 calories of energy. Goldfish require a high-carb diet, while tropical fish rely on a high-protein diet.
Goldfish | Tropical Fish | |
Lifespan | Up to 20 years | 3 to 5+ years |
Diet | Bloodworms, daphnia, brine shrimp, vegetables, dry flakes, dry pellets, small fish, etc. | Glass worms, flakes, pellets, mealworms, daphnia, brine shrimps, etc. |
Colors | Orange, red, yellow, blue, grey, brown, black, and white | Self-colored, multi-colored, and transparent |
Behavior | Social and peaceful | Smaller species are peaceful, but the larger ones can be aggressive |
Heaters and Filters | No heaters required; filters are necessary | Heaters are necessary to maintain temperature |
Water Temperature | 68˚F or less | 71.6˚F –78.8˚F |
Maintenance Level | Easy | Easy to hard (depending on the species) |
Average Size | 1 to 14 inches | 1 inch to 1 foot |
Required Tank Size | Minimum 20 gallons capacity | Minimum 10 gallons capacity |
Feeding Type | Low and bottom feeders | Top feeders |
Nutritional Needs | 30% protein and high carbohydrates; little or no mammalian fats; | 30% to 45% protein and less carbohydrates |
Differences Between Goldfish Food and Tropical Fish Food
Almost every pet store sells tropical fish food in abundance, making it easy for fish keepers to substitute goldfish food with tropical fish flakes and food. However, this is not recommended due to the inherent difference between both food types and dietary requirements.
The differences are minimal but can have a lasting impact on goldfish’s health. Furthermore, many tropical fish are caged for farming, and their diet is monitored by the fish keepers (for commercial purposes).
Goldfish flakes are made with fish meal and algae and have added minerals and nutrients. It contains around 20% to 45% protein and 3% to 10% fiber. The fiber content ensures that goldfish don’t suffer constipation or digestive issues.
Tropical fish flakes have high protein (more than 40%) and less fiber (some brands have less than 1% fiber). Tropical flakes don’t have added vitamins and are entirely protein-based.
Tropical food can give a protein boost to your goldfish when used occasionally, but substituting their food entirely with tropical fish food will affect their health in the long run.
It’s vital to find fish food that doesn’t contain too many starchy carbohydrates and too much fat. Excess of both is not recommended for goldfish and tropical fish.

What Happens When Goldfish Eat Tropical Fish Food?
You may not see any short-term issues when goldfish eat tropical fish food. However, tropical fish food is not sufficient for goldfish. The high protein content, without enough carbs and fiber, will affect their growth.
An inadequate diet might lead to protruding bones, rapid breathing, and high stress in goldfish. The high protein level in the tropical fish food will produce more waste in the goldfish’s body.
The goldfish may suffer from digestive issues and swim bladder disorder, as a result. They may look smaller, not grow fully, and have a reduced lifespan.
What Goldfish Eat in the Wild
A goldfish is naturally omnivorous and will not hesitate to eat small fish. They eat the following in the wild:
- Algae
- Aquatic plants
- Live earthworms
- Brine shrimps
- Small snails
- Zooplankton
- Amphibian larvae
- Fish eggs
- Detritus
- Small crustaceans
- Aquatic insects
As poikilothermic fish, the frequency and quantity of goldfish’s diet depend on the water temperatures and ecosystem. Goldfish eat less in colder temperatures and increase their intake in warmer temperatures. They eat small amounts of food multiple times per day.
Recommended Goldfish Diets and Feeding Guidelines
Being bottom feeders, goldfish eat underwater and prefer foods that sink and settle at the bottom of the tank. Though goldfish can pick tropical flakes from the surface of the water, they prefer live food and wet food more. An inadequate diet can lead to protruding bones, rapid breathing, and high stress in goldfish.
Some brands of dry goldfish food have 40% protein but contain 44% carbohydrates and 10% fats. This is different from what goldfish needs, so you combine goldfish pellets, flakes, frozen goldfish food, and live food to create a balanced diet.
Goldfish can be fed with the following (in moderation):
Dry Food
Goldfish flakes are easily available and well-known dry fish food. However, flake foods should be fed in moderation for three reasons:
- Flakes disintegrate faster and pollute tank water faster
- Goldfish gulp too much air when eating flakes and can end up with swim bladder disorder
- Flakes lose their nutritional value when exposed to air
Pellets are a better option as they have more nutrients and can be soaked in water before feeding goldfish.

Freeze Dried Food
Freeze-dried foods provide protein to goldfish and should be a part of their diet. However, overfeeding should be avoided. Many pet owners prefer freeze-dried food as it offers nutritional value similar to live food and is easier to feed.
Live Food
Goldfish love live foods. It’s what they find in the wild. Nevertheless, live food will make the tank messy. You will have to clean the tank more frequently. Live foods can also be expensive.
Vegetables
The fish meal should include green vegetables like shelled peas (thoroughly cooked). Cucumbers, lettuce, spinach, and kale are other veggies to feed goldfish. Peas are a must to prevent constipation.
Conclusion
Goldfish don’t mind eating tropical fish food, but it shouldn’t be a part of their daily diet. Unlike the tropical fish, the goldfish require an adequate amount of fiber along with proteins to live a healthy life.
You can, however, combine the protein-based tropical fish food pellets with other foods, such as vegetables. A combination of plant and animal-based diets will keep them active and healthy for years.
FAQs
Will goldfish eat algae in the tank?
Yes, the alga is a part of the goldfish diet. However, if your pet goldfish are regularly hunting for algae, it’s a sign of hunger or malnutrition.
Can I keep goldfish and tropical fish in the same tank?
It is not recommended to keep goldfish with tropical fish. They require different water temperatures and varieties of food to be healthy.
Will goldfish eat smaller aquarium fish?
Yes. Goldfish will eat any small fish and snails in the aquarium. They should be housed with other freshwater species of similar size to avoid such accidents.
Brian wasn’t just another Civil Engineer. His passion for Aquarium life was unknown to many until he decided to showcase it for the world. It seems like he made the right decision after all!