So, you’ve noticed your betta fish hanging out at the top of your aquarium? It’s hardly surprising that you’re feeling concerned.
There can be several reasons why your betta fish is staying at the top of your fish tank. Some of them are quite harmless, while others are more serious and may even require immediate intervention to save your fish’s life.
Let’s take a look at the top causes of a betta fish hanging around near the water’s surface and how to address the problems that it could indicate.
Reasons Your Betta Fish is Staying at the Water’s Surface
Lack of Oxygen
Betta fish have a superpower. Not only can they breathe oxygen from water with their gills like other fish, but they can also breathe oxygen from the air using their specially adapted labyrinth organ!
But this doesn’t mean that bettas enjoy being kept in low-oxygen environments!
Where there are sufficient dissolved oxygen concentrations in the water, they will happily spend much of their time in the mid-upper reaches of the aquarium, primarily using their gills to respire oxygen from the water.
But if your betta is spending all his time at the surface of the water, gasping for air, you might have an oxygen deficiency in your water. A potentially serious problem – especially if you have other fish or invertebrates in the tank that can’t breathe oxygen from the air.
Fortunately, low oxygen levels can easily be corrected by installing a good filter, making regular partial water changes, and ensuring good all-around aquarium maintenance and clean water conditions.
Asking for Food
If your betta is actively swimming around at the surface of your aquarium, looking lively and energetic, the chances are that he just wants feeding!
Whereas a severely stressed or sick fish will appear almost motionless with clamped fins, a hungry betta will be much more active, almost as if he wants to get your attention and say: ‘Hey, over there! It’s feeding time!’
But although it’s cute, be careful not to give in to your betta’s pleas for food! Overfeeding is one of the main causes of ill health and poor water quality in betta tanks, and their gluttonous appetites mustn’t be indulged!
Feeding your betta twice a day with only as much food as they can eat in 2 minutes is plenty, and having a well-defined feeding regime will also discourage your betta from wasting time and energy by begging for food all day.
Building a Bubble Nest
There’s a curious behavior among male betta fish that not everybody realizes when they get their first betta tank, and it’s all about bubbles!
Betta fish are bubble nest builders – floating foam structures that the male betta fish builds to harbor and protect the fertilized eggs after mating with a female. Bubble nests are made from a mixture of saliva and air bubbles, and often incorporate pieces of floating plant matter, too.
When your betta is building his bubble nest, he might spend the majority of his time at the water’s surface, dedicated to his important task!
But why is your male betta building a bubble nest if there’s no female around? Well, perhaps he’s hoping there’s one just around the corner! In the wild, male bettas regularly build bubble nests as part of their courtship display to show potential females that he is a ready, willing, and capable mate to father her young.
Bubble nest building is a welcome sign that your male betta is in excellent health, and at the top of his game. You need do nothing, except sit back and admire this miracle of nature.
Swim Bladder Issues
Swim bladder disease, also known as swim bladder disorder, is a common ailment in betta fish, normally caused by overeating.
A fish’s swim bladder is a special organ filled with air that regulates the fish’s buoyancy and orientation in the water.
If something goes wrong with the swim bladder, a betta fish can struggle to maintain its position and may swim on its side, upside down, near the bottom of the tank, or get stuck at the top of the tank.
A betta that overeats is prone to bloating, constipation and, in extreme cases, swim bladder problems. But swim bladder problems can occasionally be caused by other health issues, too, such as bacterial and parasitic infections.
Swim Bladder disorder can normally be remedied by fasting your betta, feeding them cooked peas as a laxative, or in more severe cases, by using Epsom salts.
If there is an underlying disease, you need to address that too. In most cases, if you treat the condition promptly enough, your pet betta should make a full recovery back to being a healthy fish.
Ammonia and Nitrite Poisoning
Ammonia and nitrites are some of the most toxic chemicals to fish and are produced by rotting fish waste, uneaten food, and dead plant material.
In a tank that’s not properly cycled and filtered, ammonia and nitrite levels build up, causing burning on your fish’s gills and making it difficult for them to breathe. Your betta’s natural instinct in this situation will likely be to gasp for air at the surface of the water.
Ammonia and nitrite poisoning is extremely serious and can kill your fish within hours. If your betta has reddish gills, inflamed eyes, and appears lethargic, you must test the aquarium water using a reliable test kit as soon as possible to see if your water contains ammonia.
If either nitrite or ammonia levels exceed 0.25 ppm, you must immediately perform an emergency water change of 30-45%, or use a water conditioner such as Seachem Prime as a temporary fix while you work on the underlying issue.
Ammonia and nitrite problems are almost always connected to an ineffective biological filter and poor tank maintenance. You can learn more about keeping ammonia and nitrites at zero from our in-focus guide here.
Bettas are aggressive fish, and many people choose to keep them alone.
But if you do decide to keep one with other species of fish, don’t overstock the tank. Betta fish need plenty of free swimming space and can either get aggressive or stressed and depressed if they’re constantly bombarded with other fish in crowded conditions.
Larger fish like gouramis that can attack your betta should never be kept in a betta tank, and even other small fish like tetras and danios should only be kept in betta tanks of at least a 20-gallon capacity.
For aquariums smaller than this, I’d only recommend keeping bottom dwellers such as dwarf and pygmy corydoras catfish with your betta, or clean up crew invertebrates such as Amano shrimp or nerite snails.
If other middle-surface layer swimmers are kept alongside a betta in a nano tank, they will quickly stress him out, and your betta might respond by sulking, sometimes motionless at the upper edges of the tank.
Low Water Temperature
When I introduced my first betta to my aquarium many years ago, he tended to hang around at the surface of the water. I later realized that my water was probably too cool for him.
Whereas most of my other community tank fish were happy in water temperatures of around 76 Fahrenheit, bettas are warmth-loving fish that prefer a temperature range of between 78 – 81 degrees Fahrenheit.
The reason that betta fish will move towards the surface in a tank that’s too cool is that warm water tends to rise to the surface of the tank, meaning the upper layers of water will be the warmest place!
And even if your thermometer is showing 78 Fahrenheit next to your aquarium heater, if your water circulation isn’t strong enough, then other parts of the tank may be a little cooler. Try placing your thermometer near the center of your tank for a more accurate reading.
Bettas don’t like strong currents, but to be sure that all parts of the tank are warm enough, it’s a good idea to position your filter’s output flow close to your heater so that the heat is distributed evenly throughout the tank.
High Water Temperature
It may seem surprising, but your betta might also be hanging out at the top of the tank because of water temperatures that are too high!
A betta’s temperature preference for 78-81 Fahrenheit is quite a tight range, and if temperatures exceed this, oxygen levels may begin to go down.
As opposed to a betta fish that’s simply residing at the surface to stay warm though, a betta that’s struggling for enough oxygen will be constantly breathing from the surface.
Follow the guidance given above to get accurate temperature readings and even heat distribution in your tank, and turn down your heater’s thermostat if necessary.
Lack of Aquarium Decor and Boredom
Bettas are intelligent fish and need adequate stimulation to remain happy and healthy. In the wild, bettas come from waters that are full of plants, driftwood, live foods, and other fish to keep them interested and entertained.
If you keep a betta in an aquarium devoid of decor, your betta may become bored, and depressed, and hang around the water’s surface as if wishing he were somewhere else.
Luckily, you can do wonders for your betta’s mood and well-being by offering him a beautiful, densely planted aquarium with pieces of driftwood to explore. A few robust tank mates such as shrimps and snails will also add interest for both of you and save your betta hours of anxious agitation near the top of the tank.
Another Sickness or Disease
While we can speculate about many specific causes as to why your betta might be hanging around at the top of the tank, it’s also a fairly typical symptom of ill health and an unhappy fish.
The other reasons that your betta might be feeling unwell are myriad. Parasitic diseases such as ich (white spot disease), velvet, and flukes. Bacterial infections like cotton mouth and fish tuberculosis. Fungal infections like water molds. All of these are serious conditions and need swift attention to avoid your betta becoming more sick or dying.
It’s a good idea to get a basic grasp of the symptoms of the most common betta diseases so that you can recognize them and treat them promptly if you see a problem.
You can learn much more about betta fish diseases, their symptoms, causes, and how to prevent and treat them from our disease archive section of the website.