What Causes Guppies to Swim at the Top of the Tank?

Pet fish owners’ number one choice would be Guppies because of their vibrant colors and their playful swimming patterns. In other words, a tank filled with guppies is a wonderful display!

What causes my guppies to swim at the top of the tank? This is an indicator of the shortage of oxygen or the lack of it completely. Another possibility would be that the tank could be deep and the guppy wants to rest its gills and get more oxygen by floating.

In this article, we will discover why a guppy fish might swim close to the surface of water.

Guppies’ swimming behaviors

It is always a good idea to get a group of 6 or more guppies together and place them in the same tank. They are sociable creatures and they get along easily.

It is recommended to place with them in the same tank some other fish types like neon tetras, catfish and platies for example. Peaceful little fish would make great companions for guppies.

Guppies are very peaceful creatures. They do nip at other fish’s fins as many fish do, but this behavior is not a means of attack or animosity, it is just an instinct.

Now when we talk about the guppies’ swimming behaviors, it is necessary to detect their manners of swimming and patterns. Guppies swim actively all around the tank. They will be scattered everywhere and not in a specific fixed manner.

Unlike the neon tetras who swim in schools, guppies swim everywhere in any direction independently. Their random swimming pattern makes them look interesting and playful.

Therefore, it is always going to be easy to realize that there is a problem with a guppy if this swimming behavior changes all of a sudden.

In this case, immediately check the water and the lighting. When guppies are hungry, you will notice that they are swimming at the top of the tank waiting for their feeding time.

Guppies are greedy eaters. Even though their bellies could be filled with so much food, you would still find them hungry and begging to be fed again. Yet, you should never feed them more than twice daily. Plus, their food should be in flakes and small pieces.

They are very similar to neon tetras this is why it is always easier to keep these two species in the same tank for they share the same tank requirements. In addition to that, you would have a fantastic colorful and cheerful tank filled with fish in vibrant cute colors. Seems like a great idea for beginners as well!

Guppies’ fins

Guppies’ fins are very interesting to pay attention to. Guppies have a special capability to spread out their fin rays. This is a sign of healthy guppies, by the way, do not be confused or concerned.

However, you might really need to be worried if you get guppies with fins pressed against their bodies. This could indicate illness or stress. When you notice the guppies’ fins pressed against their bodies, pay attention to other signs that could be indicating a serious problem in the guppies’ health.

These signs are white spots, dots or patches on the fins, holes or ribs as well. These signs mean that the guppy is not in a healthy state and needs to be checked by a vet.

If you are in a pet store struggling to choose healthy guppies, stay away from guppies with ragged fins because this is an indicator of fin rot and that the guppy is not healthy. So, fins sum up the health state of a guppy. Always keep an eye on that part of the guppy’s body! It is certain you will realize a lot!


Not only are the fins important to keep an eye on, but also the head of the guppy tells a lot about its state. The guppy’s eyes should not look cloudy and at the same time stay away from guppies with protruding eyes.

Protruding eyes indicate a case named “Popeye” and it is caused because of some infections in the eyeball and behind it. Now, take a look at the gills.

If the guppy is breathing in a rapid manner and the gills are not flapping normally like any fish’s gills, this indicates a serious health case and you should call for the vet’s help immediately.

The mouth also should be checked to make sure there are no ulcers. It is always important to pick healthy guppies because any infection and illness could spread like wildfire in a tank filled with different fish species.


Now it is also better to double check for your guppy’s good health. When it comes to the body, you have to watch closely and check if the belly is swollen or not.

A swollen belly is not a good sign to see because normal guppies have rounded bellies. Healthy guppies can only have a swollen belly when they are pregnant.

There is no fear of infection or deformity when it comes to this case. Guppies with sunken bellies are not in a good health state as well because it signifies an infection.  Any spots or patches could indicate bacterial or parasitic infection.

Guppies swimming at the top of the tank

It is said that when guppies stay swimming at the top of the tank, it is because they could be suffocating and struggling with the lack of oxygen in the water.

Therefore, you need to have an oxygenating pump to keep the suitable amount of oxygen in the water. It is not healthy for guppies to inhale air at the surface of the water. It would also be a good option if you get the water moving.

Related Questions

Do guppies breathe air?No, they do not. They need oxygenated water to breathe.

Do guppies need a filter? It is not necessary to keep a filter for the guppies because they do not produce much waste like the neon tetras. But filters would always help in purifying the water so it would help of course improve the water conditions.

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Nadine Oraby

My name is Nadine; I am a passionate writer and a pet lover. People usually call me by the nickname “Joy” because they think that I am a positive and joyful person who is a child at heart. My love for animals triggered me to create this blog. Articles are written by vets, pet experts, and me. Thanks for visiting. Your friend, Nadine!

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