Betta Fish Staying at Top of Tank: Reasons + What to Do.

Betta fish move to the top of the tank from time to time when drawing oxygen or seeking to experience a different range of temperature. However, you should be more concerned if it stays there for a long time without swimming downward or to other parts of the tank. It could be a result of crowdedness, bladder issues, food shortage, among other reasons discussed later in this article.

Is it normal for Betta fish to stay at the top of the tank?

No. It’s not normal for your betta to remain at the top of the aquarium for too long. Occasional appearances from time to time are common, but it is alarming when the betta remains there for more than 30 minutes. If you notice this behavior, it’s advisable to investigate the cause and act accordingly.

Why is my betta staying at the top of its tank?

As mentioned earlier, your betta can stay at the top of its tank due to low concentrations of oxygen, unfavorable temperatures at the bottom, hunger, and lack of enough swimming space. Follow the following information for further explanation.

Inadequate space

Betta fish enjoys the freedom to swim around and do multiple stunts. A crowded tank can limit this movement, making your fish opt to swim to the top and remain there.

For example, if you keep many tetras with one betta in a small tank, your betta may not get space to create a territory.

Like in other animal habitats, other conflicts may arise, giving the more aggressive fish an advantage over the weaker ones. In such a situation, you will notice bettas swimming to the top as a retaliation mechanism from danger.

Unfavorable water conditions

Betta fish require a particular composition of water to remain comfortable at the bottom or middle parts of the tank. A pH level lower than six or higher than eight can cause the fish to swim to the top, seeking a more habitable zone. The bettas react in the same manner when the water’s salinity, temperature, and chemical composition are not conducive.

Low concentrations of oxygen

You’ll know when your betta swims to the top in search of oxygen as they keep opening and closing their mouths, gasping for air. Unlike other fish who get oxygen from water using their gills, bettas can breathe from the surface through their labyrinth organ.

With this breathing structure, betta fish can breathe like people because it’s structured to function like lungs. When experiencing oxygen deficiency, they will move to the tank’s topmost surface, with a higher concentration of dissolved oxygen than other parts.

Inadequate Food

Lacking enough food can make your betta fish stay at the top of the tank. They are conditioned to understand that food is placed inside the tank from the top making them swim nearer to the surface.

After searching for food throughout the tank without any success, your fish will move to the top and remain in waiting.

Problems with the swim bladder

Betta fish with swim bladder problems tend to move to the top of the tank and keep floating. Swim bladder issues mainly result from constipation and overfeeding. Look out for any swells and stringy fecal matter which hangs from the fish’s back.

This problem makes the fish lie on its side while at the top of the tank. It also lacks enough stability to swim straight due to the discomfort.

What to do if the fish stays at the top of the tank

Among the recommended remedies to keep your betta fish away from the top of the tank are regulating oxygen concentration, setting a favourable temperature, treating the tank water, getting an aquarium that’s big enough and feeding your fish with quality food. You should first understand the external factors causing that.

Regulate the tank’s oxygen concentration

Adding substances like the air stone to the tank increases the concentration of oxygen in the water. It speeds up the escape of CO2 from the water while enhancing the rate at which oxygen dissolves

If your fish swims to the tank top to gasp for air, it’s advisable to purchase the air stone and boost oxygen creation within the aquarium. For large fish tanks, get powerheads which are more powerful for faster distribution of oxygen. This helps your betta fish swim in all parts of the tank without sticking to the top only.

Set a favourable temperature range and balanced parameters

The water temperature in betta fish tank should be between 70° F and 80° F. Lower temperature is unbearable to your betta as it sends its body into shock. Using a thermometer, make the necessary measurements and adjustments to prevent your fish from swimming to the top for a longer period than normal.

You should also ensure that other parameters like salinity, pH and chemical composition of the tank water are balanced. You can achieve this using water conditioners.

Keep the tank water in high quality

High quality aquarium water is free from ammonia, nitrites, nitrates, chlorine and other chemicals capable of poisoning your betta fish. The fish swims to the top of the tank to evade the risks arising from water that has too many foreign substances.

Keep the tank gravel and decorations  clean by washing off waste and excess foods. Change the water often to avoid accumulated dirt that’s inhabitable for the fish, causing it to remain at the top of the tank.

Get a bigger tank

Bigger tanks are best suited to hold many betta fish and prevent overcrowding. It also reduces conflicts because each fish has enough space to swim around instead of being stuck at the top.

Give your bettas proper food and check for swim bladder issues

To avoid getting your betta fish constipated, do not feed them too much food. If they are already showing signs of swim bladder problems, refrain feeding them for about two days. Upon resuming their feeding routine, feed the fish peeled boiled peas to forcefully remove fecal waste.


The main reasons for your betta fish to stay at the top of the tank are distress or discomfort resulting from external factors in their habitat. An overcrowded fish tank forces some fish to move upward to the surface where it’s likely to be less populated. Other distress factors include bladder problems, imbalances in the water parameters, dirty environment and lack of oxygen.

You can reverse this by following the listed solutions and watch your betta fish thrive as they explore every part of the tank instead of only remaining in the topmost surface.

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