Is Your Betta Breathing Heavily? – Causes and Treatments

Charlie Morton

Charlie Morton


Betta Breathing Heavy

Sharing is caring!

If you’ve noticed your betta breathing heavily, you have good reason to be concerned.

Heavy or rapid breathing is a classic sign that something is not right either in your betta’s health or the aquarium environment.

Here we’ll look at some of the main reasons that your betta might be breathing fast, and what you can do to correct them.

Causes of Heavy Breathing In Betta Fish

Low Oxygen Levels

The most obvious cause of a betta fish breathing heavily is a lack of dissolved oxygen in the water.

Even though betta fish are labyrinth fish and can breathe oxygen from the air with their labyrinth organ, they also like to breathe a portion of their oxygen intake from the water.

If the tank’s oxygen levels are low, the fish may breathe more heavily, appear lethargic, and gasp at the surface to breathe air – a condition known as hypoxia.

A good way to tell if oxygen levels are the cause of the problem is to observe the other tank mates that share the tank with your betta. If they are also breathing heavily without sore, red gills then oxygen deprivation is indeed the most likely cause.

The Solution

If you have one available, test your betta tank’s water with a reliable oxygen test kit to confirm whether oxygen deficiency is the source of the problem. If you don’t, you need to act immediately to be on the safe side anyway.

Sera Oxygen-Test (O2)

Quick breathing at the water surface is an unmistakable sign for an oxygen deficiency. Unfortunately, it may then already be too late for acting appropriately.

Check Price on Amazon

Perform an emergency 50% water change with fresh, treated tap water to replenish your tank’s oxygen supplies immediately. After that, you can try to fix the root cause of the problem – for example overcrowding, an ineffective filter, or a water temperature that’s too high.

High Water Temperature

Betta fish prefer aquarium water temperatures between 78-81 Fahrenheit. If the temperature rises above this, there will be less dissolved oxygen in the water and your fish may have trouble breathing normally.

High water temperatures can often be attributed to a faulty thermostat on your aquarium heater, hot weather that’s consistently over 80 Fahrenheit, or direct sunlight that’s shining on the tank, heating up the water.

The Solution

Your best defense against high water temperatures is a reliable aquarium thermometer with which you can monitor the aquarium’s temperature on a daily basis.

Avoid placing your tank in direct sunlight, and keep your aquarium in the coolest room of the house if you often suffer from summer heat waves.

If you discover your tank’s temperature is too high, you can reduce it by placing ice cubes in sealed bags in your aquarium. Keep a close watch on your thermometer and remove the ice when the water is back to a safe temperature.

No Aquarium Filter or a Broken Filter

One of the myths about keeping betta fish is that you can keep them in a fish bowl and they don’t require an aquarium filter. Although you might be able to keep a betta in a fish bowl for a short time, its lifespan would be dramatically reduced if they were to stay there.

Without a filter, your water will be prone to ammonia spikes, low oxygen levels, and poor water quality, all of which will cause your poor betta’s gills to pulse as they struggle to survive.

Likewise, a broken filter or an aquarium filter that has insufficient beneficial bacteria will not biologically filter the tank’s water properly and can result in ammonia spikes and oxygen depletion.

The Solution

Always keep your betta in a well-maintained, filtered aquarium that’s at least 5 gallons in size.

If your filter has broken, you’ll likely experience an ammonia spike soon after. Test your tank’s water with an API Master Kit and perform an emergency 50% water change if necessary.

API Water Test Kit
  • Accurately monitors 5 most vital water parameters levels in freshwater aquariums: pH, high range pH, ammonia, nitrite, nitrate
  • Designed for use in freshwater aquariums only
  • Use for weekly monitoring and when water or fish problems appear

Check Price on Amazon
We earn a commission if you make a purchase, at no additional cost to you.

Continue to make daily 20% water changes until your biological filter is properly functioning and your tank is cycled again.

Ammonia Spike

Ammonia is the nitrogenous waste product that is excreted in fish feces, and it just so happens to be one of the most toxic substances to fish.

High levels of ammonia or nitrites can cause serious burns around fish’s gills, as well as lethargy and gasping for air. It is caused by an unsanitary tank environment, poor-quality water, and an inefficient or broken filter.

Ammonia poisoning is one of the most serious health conditions your betta can suffer from, and if it’s not corrected quickly your betta could easily die.

The Solution

If you suspect an ammonia spike, act quickly. Test your water with an API Master Kit if you have one to hand, but if you don’t the behavior of your fish listed above should confirm the cause of the problem.

Perform an emergency 50% water change and work to determine the cause of the high ammonia level. Check your filter, and transfer some filter media from a healthy biological filter to yours to boost the beneficial bacteria that convert ammonia to nitrates.


Stress may just be the biggest underlying cause of ill health in betta fish. A stressed betta will have a weakened immune system and is more vulnerable to infection from an array of pathogens.

Breathing heavily is one of the tell-tale signs that your betta is stressed. If it is a mild case, they may simply hang around near the water’s surface breathing more rapidly than normal.

But in serious cases of stress or shock, your betta may lie at the bottom of the tank, fairly motionless, beating his gills quickly.

The Solution

In a serious case of stress or shock, the best thing to do may be to turn the aquarium’s lights off and let your fish rest. Work to determine the cause of the stress as quickly as possible. Check the water temperature, water chemistry, and oxygen levels.

If you think that stress could have been caused by bullying from an incompatible tank mate, remove the troublemaker or place your betta in a different tank where it’ll be safe.

Adding plenty of live plants and hiding places is a fantastic way to help your betta feel more at home, reduce stress levels, and improve water conditions too.

Chemical Contamination

There are many chemicals that may seem fairly harmless to us but are highly toxic to fish. If your bettas are exposed to these contaminants, they’ll likely become distressed and begin to breathe very fast.

Soap, for example, may seem relatively harmless, but did you know that the saponins that soap contains are incredibly toxic to fish? Even a tiny amount of soap or washing-up liquid used to clean some aquarium equipment could cause serious poisoning in your fish.

Other toxins for fish include deodorant and other aerosols, detergents, fluoride, and chlorine. Because these last two are normally included in municipal drinking water, it’s essential to purify your tap water with a water conditioner before adding it to your betta tank.

Aquarium Water Conditioner
  • Contains one (1) API TAP WATER CONDITIONER Aquarium Water Conditioner 16-Ounce Bottle
  • Neutralizes chlorine, chloramines and other chemicals to make tap water safe for fish.
Check Price on Amazon

The Solution

Prevent chlorine contamination by always treating your water with a water conditioner first. Only clean your tank and aquarium equipment with aquarium-safe cleaning products, and keep the tank’s lid closed to avoid contamination from aerosol sprays or air fresheners.

If you think your betta fish is suffering from chemical poisoning, make a 50% partial water change with treated water of the right temperature. After that, continue to change 10% of the tank’s water every day until symptoms improve.

Overcrowded Tank

Overcrowded tanks are a disaster for betta fish health, and can cause heavy breathing for multiple reasons.

Firstly, overstocked tanks are very stressful environments for pet bettas. Bettas are territorial fish that like to stake out their own turf and have plenty of room to call their own.

A single betta needs a tank size of at least 5 gallons. If you want to add a few compatible tank mates to the mix, you’ll need at least a 10-gallon tank.

If a tank is overstuffed and other fish are constantly entering a betta’s territory, your pet fish might become aggressive or feel vulnerable to attack – both of which will cause them to stress out and breathe fast.

Overcrowded fish tanks also tend to suffer water quality issues more often, and can easily become depleted in oxygen or high in ammonia or nitrites.

The Solution

Calculate the maximum stocking capacity of your tank using the one gallon per one inch of fish rule. If you have a 10-gallon tank, you’ll be able to fit a combined length of 10 inches of fish in it.

Since your betta fish is already 3 inches long, you could, for example, also add a couple of small corydoras catfish to make up the remaining 7 inches.

If your combined length of fish is more than your tank size, you’ll need to rehouse some of the fish or get a larger tank!


Betta Breathing Heavy

Bettas are not called Siamese fighting fish for nothing! These feisty characters will rarely turn down a ruckus, but fighting can also cause them substantial stress and labored breathing.

Each betta fish will have a different temperament, and some bettas will happily share a tank with other peaceful fish.

Aggressive bettas, however, will flare at and attack just about anything that moves, including their own reflection. Chronic aggressive behavior doesn’t let your fish rest and can quickly lead to health problems.

The Solution

If your betta is triggered into aggressive behavior by other fish, it may be better for both your betta and the others to keep them in separate tanks. Male bettas should never be kept together for this reason.

If your betta is flaring at and attacking his own reflection, you can keep a bright light on the outside of the tank to reduce the brightness of his reflection. Also, turn his tank light off for at least 12 hours each night to give him a chance to rest.


Another common cause of rapid gill movement in betta fish is when they’re suffering from a disease or health condition that’s causing them stress or interfering with their normal gill function.

Ich, velvet, dropsy, and swim bladder disorders are common ailments in betta fish, and all of them can cause heavy breathing, especially if the fish becomes heavily infected.

Parasites like gill flukes and anchor worms that directly affect the gills will cause acute rapid breathing, and can even be fatal if not treated promptly.

The Solution

The short-term solution to illnesses is obviously to treat the disease. This will be different for each malady, but in some cases a specially dedicated hospital tank is appropriate.

In the longer term, your best way to prevent diseases is by keeping your betta healthy with a diverse, high-protein diet and keeping your water in tip-top condition!

Check out this guide to betta health to learn how to diagnose and treat various diseases.

Cases Where Your Betta May Only Appear To Be Gasping For Air

Anticipating Food

If your betta fish is gasping at the surface of the water, it might not be because of any of the above conditions at all, but instead from the anticipation of food!

Bettas are notoriously greedy fish who seem to have an almost insatiable appetite for food. When you approach your betta tank, your appearance might trigger your betta to think it’s feeding time and open and close his mouth at the water’s surface. (Maybe he’s giving you a hint!)

This behavior isn’t actually related to heavy breathing at all, but could get confused with it in some bettas that are particularly eager for feeding!

Building a Bubble Nest

The final reason we’ll look at for a betta gasping at the surface is also not really related to heavy breathing at all, but building a bubble nest.

Male betta fish are one of the few fish in the world that exhibit a fascinating breeding behavior where they’ll build a nest out of bubbles to place the female’s eggs! Bubbles are collected in a betta’s mouth and deposited in a floating mass with sticky saliva to hold them together.

Even if you only have a lone male betta, he may still build a nest, anticipating the female of his dreams that might be just about to enter his tank. Cute, right?


Betta fish breathing heavily can be a symptom of several different health or environmental causes, all of which should be corrected quickly before they become a serious problem.

In a few cases, what appears to be heavy breathing may be your betta gasping at the surface for a different reason.

By using this guide and observing your betta closely, we hope you’ll be able to determine the cause of your betta’s behavior and work to remedy it before it’s too late.

You can learn more about betta health and illnesses, including some of the issues we’ve listed above here.

Sharing is caring!

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.