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Why Are My Neon Tetras Blowing Bubbles? (5 Quick Solutions)

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Fish like neon tetras can blow bubbles for natural reasons. However, if they do that persistently, especially at the top of the tank, it usually suggests that something is wrong.

When I first faced that issue I had no idea what to do. Fortunately, over the years, I gained some experience in this topic.

In this article, I will show you what might cause this behavior, and what steps you can take to fix it fast. Let’s get into it.

Why Are My Neon Tetras Blowing Bubbles?

If you witnessed your neon tetras blowing bubbles excessively, it can be due to any of the following reasons:

1. Lack of Oxygen

If the oxygen levels in the water drop, neon tetras may resort to unusual behaviors like blowing bubbles as a distress signal:

  • Poor aeration: If the aquarium isn’t equipped with an air pump or doesn’t have enough live plants, it might not provide enough oxygen for the fish, forcing them to blow bubbles.
  • Overcrowding: Excessive fish population in an aquarium can deplete the oxygen levels rapidly, resulting in the fish resorting to blowing bubbles.
  • Insufficient water surface movement: Surface agitation helps oxygenate water. Without it, oxygen levels might drop, triggering bubble blowing.
  • Algae bloom: Overgrowth of algae in the tank can reduce oxygen levels significantly, especially at night when photosynthesis is halted, causing fish to blow bubbles.
  • Decaying organic matter: Dead plants, uneaten food, and fish waste, if not removed timely, can consume a lot of oxygen, causing fish distress.

Also Read: Why Are My Neon Tetras Breathing Fast?

2. Low Water Quality

The water quality in an aquarium has a profound impact on the health of neon tetras. Poor water conditions can lead to stress and changes in behavior, like blowing bubbles:

  • High ammonia levels: Ammonia, produced from fish waste, can become toxic if not efficiently removed, leading to increased bubble blowing.
  • Imbalanced pH levels: Neon tetras prefer slightly acidic water. An imbalance in pH can cause stress and unusual behaviors.
  • High nitrate levels: Excessive nitrates, a byproduct of the nitrogen cycle, can harm fish, causing bubble blowing.
  • Presence of harmful chemicals: Certain chemicals, like chlorine or heavy metals, if present, can distress fish.
  • Infrequent water changes: Regular water changes are essential to keep the water quality high. Infrequent changes might lead to adverse conditions.

Also Read: Why Is My Neon Tetra Gasping For Air?

3. High Temperature

Temperature plays a critical role in the well-being of neon tetras. High temperatures can lead to behavioral changes, including bubble-blowing:

  • Reduced oxygen levels: Higher temperatures lower the oxygen capacity of water, causing distress to fish.
  • Increased metabolism: Warmer temperatures speed up fish metabolism, leading to increased oxygen demand and possible bubble blowing.
  • Accelerated bacterial growth: High temperatures favor bacterial growth, which can contribute to disease and stress.
  • Increased toxicity: Certain toxins, like ammonia, become more harmful at higher temperatures.
  • Thermal shock: Sudden temperature changes can cause severe stress, leading to abnormal behaviors.

4. Gas Bubble Disease

Gas bubble disease is a condition that affects fish due to the supersaturation of gases in the water. This can lead to bubble formation in the body and gills of neon tetras:

  • Improper decompression: Sudden changes in pressure can lead to gas supersaturation, causing this disease.
  • Faulty equipment: A faulty air pump or filter could introduce excessive gas into the aquarium.
  • High altitude: Aquariums located at high altitudes can be prone to higher gas concentration.
  • Rapid temperature changes: Rapid warming can lead to supersaturation of gases, contributing to this condition.
  • Excessive aeration: While aeration is crucial, overdoing it can lead to gas supersaturation.

5. Stress

Stress in neon tetras can lead to changes in their behavior, including bubble blowing. Many factors can contribute to stress in these fish:

  • Inappropriate tank mates: Neon tetras prefer a peaceful community. Aggressive tank mates can cause significant stress.
  • Inadequate hiding spots: Lack of sufficient hiding spots can make the fish feel vulnerable, leading to stress.
  • Poor diet: An imbalanced diet can weaken the fish’s immune system, causing stress and unusual behavior.
  • Incorrect lighting: Neon tetras are sensitive to bright lights. If the lighting is too bright or left on for too long, it could stress the fish.
  • Disease: Any disease or health condition can cause considerable stress, leading to changes in behavior.

Also Read: Stress In Neon Tetras

How To Treat Neon Tetras That Consistently Blow Bubbles?

Dealing with a neon tetra that blows bubbles non-stop depends on the underlying reason. Consider the following:

1. Enhancing Oxygenation

Enhancing oxygenation can help your neon tetra if it blows bubbles due to oxygen deficiencies:

  • Increase aeration: Add an air pump or a sponge filter to the tank to enhance aeration and improve oxygen levels. My recommendation: Hygger Aquarium Air Stone (link to Amazon).
  • Avoid overcrowding: Maintain a reasonable number of fish in the aquarium to prevent depletion of oxygen due to overcrowding.
  • Boost surface agitation: Use a filter outlet or an air stone to cause water movement on the surface, which facilitates oxygen exchange.
  • Add live plants: Plants produce oxygen during photosynthesis, increasing the overall oxygen levels in the tank.
  • Remove decaying matter: Regularly clean the tank to remove decaying organic matter which consumes oxygen.

Also Read: Do Neon Tetras Need An Air Pump?

2. Maintaining Water Quality

Poor water conditions can cause stress and fast breathing. This is how you can fix it:

  • Regular water changes: Replace 20-25% of tank water every week to keep nitrite and ammonia levels low.
  • Use a water conditioner: This will neutralize harmful chemicals like chlorine and heavy metals.
  • Monitor pH levels: Maintain the water pH between 6.0 and 7.0, as neon tetras prefer slightly acidic conditions.
  • Keep a healthy nitrogen cycle: Use biological filtration to establish and maintain a robust nitrogen cycle in the aquarium.
  • Test water regularly: Use water testing kits to monitor levels of ammonia, nitrites, nitrates, and pH to ensure optimal conditions. My recommendation: API FRESHWATER MASTER TEST KIT (link to Amazon).

Also Read: What Is The Best pH Level For Neon Tetras?

3. Controlling Temperature

As I mentioned earlier, neon tetras may breathe fast because the temperature is too high. Here is how to control it:

  • Use an aquarium heater: A reliable, adjustable aquarium heater can help keep temperatures stable within the preferred range (between 70-81°F or 21-27°C). My recommendation: Orlushy Submersible Aquarium Heater (link to Amazon).
  • Monitor temperature: Regularly check the water temperature with an aquarium thermometer.
  • Gradual changes: If adjustments are needed, make them gradually over several days to avoid thermal shock.
  • Use a chiller: For extremely hot climates, an aquarium chiller might be necessary to maintain appropriate temperatures.
  • Reduce lighting: Excessive light can heat the water. Reduce the time the tank lights are on or use LED lights that emit less heat.

Also Read: Neon Tetra Temperature

4. Treating Gas Bubble Disease

If your neon tetra suffers from Gas Bubble Disease, it’s best to treat it immediately:

  • Identify the cause: Check for faulty equipment or sudden changes in temperature or pressure that may have caused gas supersaturation.
  • Gradual decompression: If the disease is due to a rapid pressure change, slowly lower the water pressure in the tank.
  • Equipment inspection: Ensure all equipment like pumps and filters are working properly and not introducing excess gas into the tank.
  • Consult a vet: If symptoms persist, consult an aquatic vet for professional advice and possible treatment.
  • Prevention: Keep conditions stable to prevent this disease. Avoid unnecessary agitation or sudden changes in tank conditions.

Also Read: 17 Neon Tetra Diseases & Their Treatments

5. Reducing Stress Levels

Identifying and addressing stressors can significantly improve your neon tetra’s well-being:

  • Choose suitable tank mates: Neon tetras are peaceful; ensure their tank mates are not aggressive.
  • Provide hiding spots: Add plants or decorations to provide areas for the fish to retreat and feel safe.
  • Balanced diet: Ensure your tetras are getting a varied and balanced diet to keep them healthy.
  • Correct lighting: Maintain a proper lighting schedule with periods of darkness to mimic their natural environment.
  • Health check: Regularly check for signs of disease. Early detection and treatment can significantly reduce stress.

When picking tank mates for your neon tetras, I suggest sticking to peaceful creatures like:

  • Harlequin Rasbora (Trigonostigma heteromorpha)
  • Cherry Barb (Puntius titteya)
  • Ember Tetra (Hyphessobrycon amandae)
  • Dwarf Gourami (Trichogaster lalius)
  • Pygmy Corydoras (Corydoras pygmaeus)
  • Otocinclus Catfish (Otocinclus affinis)
  • Celestial Pearl Danio (Danio margaritatus)
  • Endler’s Livebearer (Poecilia wingei)

Avoid large or aggressive fish such as:

  • Betta Fish (Betta splendens)
  • Tiger Barb (Puntigrus tetrazona)
  • Red-Tailed Shark (Epalzeorhynchos bicolor)
  • Jack Dempsey (Rocio octofasciata)
  • Convict Cichlid (Amatitlania nigrofasciata)
  • Green Terror (Andinoacara rivulatus)
  • Black Ghost Knifefish (Apteronotus albifrons)
  • African Butterflyfish (Pantodon buchholzi)

Also Read: 19 Great Neon Tetra Tank Mates


Neon tetras that blow bubbles due to rapid breathing could be due to various factors such as oxygen deficiency, poor water quality, and temperature issues.

Obviously, each cause has its own treatment, and identifying the underlying cause can be pretty challenging.

If you are unsure about what to do, I highly suggest consulting an aquatic veterinarian as the first course of action. An expert will be able to provide the right treatment.