Why You Have To Endure The Stinky Smell When Feeding Your Fish

Every day I get a whiff of a stinky smell as soon as I open the jar of fish food there’s a smell of fish coming at me. That made me thinking…

Why does fish food smell so bad? It’s mainly the protein source in the fish food smelling, but also the contained fat could be a cause of the smell.

How come our food doesn’t smell but the food we give our pets does? Let’s find out why!

The smell of fish food

To best describe the smell of fish food, you probably describe it like a fishy smell. That’s because a lot of the fish food contains fish itself as a protein source.

The protein is vital for a fish to grow properly. All fish food is containing protein and that source has to come from something rich in protein. When thinking of protein you probably thinking of muscles.

That because muscles have a lot of protein and are the perfect source for protein to your fishes in your fish tank. The protein that is easiest to get a hold of is the muscles from other fish. That’s why you often have fish in your fish food.

That’s also why the food you give your fish is smelling like the raw fish you are going to cook for dinner.

Another vital part of fish food is fat. The fat provides the fish with energy. A fat source in fish food is fish oil. The fish oil is also a source of the smell you get from your fish food container.

You should be careful with the fat in your fish food though! Too much fat could lead to damaging your fish. Mainly the liver would be damaged when giving too much fat in the diet for your fishes.

Are the fish cannibals since they eat other fish? No, they are not! There are a lot of different species of fish and there are never fishes that you have in a fish tank providing the protein source of fish food. There is a lot smaller and more easy to get fish that are the protein source. Those fishes are a completely different species.

It doesn’t make you a cannibal by eating other mammals, likewise, the wolf is not a cannibal by eating its prey. There are even fishes in the sea eating other fishes.

Different types of fish food – Any difference?

Different kind of fish has different requirement for their food. Like humans, some are vegetarians and some are meat-eaters.

It’s important to know what kind of food your fish is eating. That why you need to do your research when getting fish for your fish tank. The fish that want meat as their main protein needs food that has fish or other animal protein as the main source. Fishes that want vegetarian food also need protein and their protein source should be from plants. For example algae, soybean meal.

While getting fish you generally want fish that eat the same type of food. You can’t control which fish-eating what so it’s easier to have the same type of food for all of your fishes. There is one exception though.

The bottom dwellers are often vegetarians and they won’t come up to the surface to eat. They eat at the bottom and you should give them special food as in wafers or any other plant-based sinking food.

So, do other types of food smell different? Not really. For a trained and good nose, it might smell different but the smell is generally the same.

The different kind of food is:

  • Flakes
  • Pellets
  • Sinking pellets
  • Frozen food
  • Fresh food
  • Live food

All these food should contain mainly protein and it is, as stated before, the protein that smells bad. What makes you choose what kind of food you use as your everyday fodder is depending on your fish. The flakes are floating and after a little while sinking to the bottom. So if you have fish feeding from the surface, middle of the tank and from the bottom flakes would be a good type of food.

Fresh food is something most fishes love. You could make it your own or you could buy it from the store. Every now and then you could give a little piece of pea, zucchini and it’s a party for the fishes in your tank.

The frozen food is not smelly when frozen but you should not give your fish frozen food. You would not eat something frozen so why would your fishes do it? You have to defrost the frozen food first but then, it starts to smell.

The live food is the exception from the list. It’s not smelling since it lives. The living food is food that only the meat-eaters should eat and it’s not something you are giving every day

In fact, you should not only have one food source for your fish. You should have a variety of food just like you eat different things. I’m not saying you should have a hundred different types of food but switching it up every now and then makes your fish happy. You still have to endure the smell though.

Ingredients In Fish Food

Your fish need to eat healthy just like you have to do. A healthy diet for a fish contains mostly protein for growth. Fat and fiber for the energy and vitamins and antioxidants to keep the fish strong and healthy. There are different sources of these ingredients.

ProteinFish, soybean meal, algae, shrimp~50-70%
FatFish oil, canola oil, palm oil~10%
FiberCornmeal, wheat meal~5%
OtherAntioxidants, vitamins, minerals~15%

You should not have too much fiber in the diet it would, as too much fat will, damage your fish.

When looking at the ingredients, please be aware of our environment. As you see it could be palm oil as a fat source. Palm oil has a reputation to be damaging to the environment.

Some food contains color enhancing ingredients. It could help enhance the color of your fish but if the fish is not feeling well, it will not color out. You should not only feed the color enhancing food if you have one sort of food as you will not get the effect as you might expect. A healthy fish is coloring out as it should and will have bright vibrating colors.

To have a healthy fish you should switch up the food you are giving. The food you switching between could all be color enhancing, it’s fine and will help with the color.

You should definitely look at the ingredients when buying fish food. Your fish need to eat good food, just like you have to eat good food. The food should you provide for you fish should vary in kind and in ingredients.

Related questions

Can fish food be old? Yes it has a best-before date and the fish food will go stale

Are there non-stinky fish food? There’s not since all fish food needs to contain some sort of protein and it’s the protein that smells


I have been a fish keeper a big part of my life. During the years I have gathered and searched a lot of information about fish keeping and here, on the website, is where I share that information to help you with your fish keeping. I want to provide the information that I didn't get when I had a question about my fish tank.

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