Why Is My Angelfish Laying On Its Side? (5 Quick Solutions)

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A few months ago, I woke up to find my beloved angelfish lying on its side at the bottom of the tank. It was still alive, so I knew I had to take immediate action.

As it turned out, my fish was suffering from swim bladder disorder. However, after extensive research, I realized there could be numerous reasons behind this condition.

In this article, I’ll address all these causes, so you can help save your angelfish in no time. Let’s dive right into it.

Is It Normal for Angelfish to Lay Sideways?

No, it is not normal for angelfish to lay sideways.

This behavior is often a sign of distress or illness, such as swim bladder disorder, water quality issues, or infections.

Observing an angelfish laying sideways should prompt immediate investigation and appropriate measures to address the underlying cause.

Also Read: Stress In Angelfish

Why Is My Angelfish Laying on Its Side at the Bottom of the Tank?

Here are the most common reasons for an angelfish lying on its side:

1. Swim Bladder Disorder

Swim Bladder Disorder affects the buoyancy of angelfish, causing them to lose balance and float sideways or upside down.

This condition can stem from various causes such as overfeeding, genetics, or sudden changes in water temperature.

  • Caused by Overfeeding: Overfeeding can lead to an expanded swim bladder, significantly disrupting buoyancy and leading to the angelfish floating sideways.
  • Genetic Predisposition: Some angelfish breeds are more prone to swim bladder issues, often related to their unique body shape, causing buoyancy problems.
  • Identification Tip: Look for symptoms like difficulty in diving or uncontrollable floating to the surface, which are clear indicators of swim bladder issues.

2. Water Quality Issues

Poor water quality is a major stressor for angelfish, leading to various health problems including difficulty in maintaining their swimming posture.

  • Ammonia and Nitrite Toxicity: High levels of ammonia or nitrites in the water can cause disorientation and side-floating in angelfish, indicating distress.
  • Incorrect pH Levels: Unbalanced pH levels in the tank stress angelfish, leading to abnormal swimming behaviors and impaired health.
  • Identification Tip: Observe for rapid gill movement and faded colors in angelfish, often accompanying poor water quality issues.

3. Parasitic Infections

Parasites can severely affect the health of angelfish, resulting in abnormal swimming patterns like lying on their side.

  • External Parasites: Parasites such as Ich cause discomfort and irritation, leading to erratic swimming and sideways floating in angelfish.
  • Internal Parasites: Internal parasites can damage vital organs, affecting the fish’s buoyancy and swimming posture dramatically.
  • Identification Tip: Be on the lookout for behaviors like scratching against objects and lethargy, which can indicate parasitic infections.

4. Bacterial Infections

Bacterial infections can impact the swim bladder and other internal organs, causing angelfish to float sideways.

  • Infection of Swim Bladder: Bacterial attacks on the swim bladder can disrupt an angelfish’s balance and buoyancy, causing noticeable swimming difficulties.
  • Systemic Infections: Widespread bacterial infections can lead to general weakness and abnormal swimming in angelfish, affecting their overall health.
  • Identification Tip: Watch for signs such as ulcers, fin rot, or lethargy, which can be early indicators of bacterial infections.

5. Physical Injury

Physical injuries, either from aggressive tank mates or accidents, can lead to an angelfish laying on its side.

  • Injuries from Aggression: Attacks from other fish in the tank can cause injuries that impair an angelfish’s swimming abilities and balance.
  • Accidental Injuries: Unexpected collisions with tank decor or equipment can lead to physical trauma, affecting the fish’s buoyancy and swimming.
  • Identification Tip: Check for visible wounds, torn fins, or swelling on the fish’s body, which can be signs of physical injury.

Also Read: Angelfish Sitting At The Bottom

What to Do If Your Angelfish Is on Its Side?

Finding your angelfish lying at the bottom of the tank on its side requires immediate action. Here’s what you should do:

1. Adjusting Diet and Feeding Practices

If your angelfish is lying on its side, it may be due to dietary issues affecting its swim bladder. 

Modifying what and how you feed your fish can significantly improve its health and swimming ability.

  • Fast Your Fish: Initially, refrain from feeding your angelfish for 24-48 hours to alleviate pressure on the swim bladder.
  • Incorporate Peas: After the fasting period, feed your angelfish small portions of cooked, peeled peas, which help in digestion and can alleviate swim bladder issues.
  • Soak Dry Foods: When you resume regular feeding, soak dry foods in tank water for 5 minutes before feeding to prevent them from expanding in the stomach.
  • Feed in Moderation: After the fasting period, resume feeding with small, manageable portions once a day to prevent overfeeding, a common cause of swim bladder problems.

Also Read: How To Feed Angelfish

2. Improving Water Quality and Habitat Conditions

Water quality is crucial for the health of your angelfish. Maintaining optimal tank conditions is key in preventing and resolving issues like your fish lying on its side.

  • Regular Water Changes: Conduct 25% water changes weekly to maintain stable water conditions and reduce harmful toxins.
  • Check Water Parameters: Test water weekly for ammonia, nitrite, nitrate, and pH, keeping ammonia and nitrite at 0 ppm and pH around 6.8-7.8. I use the API Freshwater Master Test Kit (link to Amazon) for that purpose.
  • Adequate Filtration: Ensure a filtration system rated for at least 1.5 times your tank’s volume to keep water clean and oxygen-rich.
  • Tank Setup: Create a stress-free environment with plants, hiding spots, and a light cycle of 12 hours to mimic natural conditions.

Also Read: Angelfish Water Parameters

3. Treating with Anti-Parasitic Medications

If parasitic infections are causing your angelfish to lie on its side, appropriate medication is crucial for treatment.

  • Identify the Parasite: Look for symptoms like white spots (Ich) or slimy skin to identify the parasite and choose the right treatment.
  • Use Specific Medications: Apply anti-parasitic medication like copper sulfate or Praziquantel as per the product’s dosage instructions. My recommendation: Fritz Mardel Coppersafe (link to Amazon).
  • Isolate Infected Fish: Quarantine infected fish in a separate tank during treatment to prevent spreading the infection to others.
  • Monitor Treatment Progress: Observe your angelfish daily during treatment to ensure recovery and make necessary adjustments to the treatment plan.

Also Read: Angelfish Diseases

4. Administering Antibiotics for Bacterial Infections

Bacterial infections can cause angelfish to float sideways and require prompt antibiotic treatment.

  • Diagnose the Infection: Look for symptoms like ulcers or fin rot to identify bacterial infections and select the appropriate antibiotic.
  • Choose Right Antibiotics: Use antibiotics like Maracyn or Kanaplex, following the prescribed dosage for at least 5-7 days.
  • Isolate for Treatment: Quarantine the infected fish during antibiotic treatment to prevent spread and monitor recovery closely.
  • Water Changes During Treatment: Perform 20% water changes before each antibiotic dose to ensure effective treatment and reduce toxin buildup.

5. Providing Supportive Care for Physical Recovery

Physical injuries require gentle care and a stress-free environment to aid in your angelfish’s recovery.

  • Reduce Stress: Keep the tank environment calm with minimal noise and light, which helps in faster recovery of the injured fish.
  • Gentle Handling: If handling is necessary, use a soft net and minimize the time out of water to prevent further stress and injury.
  • Provide Ideal Conditions: Maintain water temperature at 78-80°F and ensure proper filtration to keep the environment stable and conducive to healing.
  • Monitor Progress: Regularly check for signs of healing or improvement in swimming behavior, adjusting care as needed for the fish’s recovery.

Will My Angelfish Recover?

The likelihood of your angelfish recovering depends on the severity of its condition and the promptness and effectiveness of the treatment provided.

If the issue, such as swim bladder disorder or infection, is identified and treated early, there’s a good chance of recovery.

Consistent care, proper tank conditions, and appropriate medical treatment are crucial for the fish’s recovery.

Why Is My Angelfish Floating on Its Side at the Top?

Your angelfish floating on its side at the top of the tank is typically a sign of a swim bladder disorder or severe stress, often caused by environmental factors or health issues.

This behavior indicates that the fish is struggling to maintain its buoyancy or is too weak to swim properly.

  • Swim Bladder Disorder: This condition, often caused by overfeeding or poor diet, affects the fish’s ability to regulate its buoyancy, leading to floating at the surface.
  • Poor Water Quality: High levels of ammonia (above 0 ppm) or incorrect pH (outside 6.8-7.8) can stress the fish, causing it to float helplessly at the top.
  • Severe Stress: Stressful conditions, like aggressive tank mates or constant changes in water temperature, can weaken the fish, resulting in abnormal floating.
  • Advanced Stage of Disease: Chronic illnesses, especially untreated bacterial or parasitic infections, can debilitate the fish, making it float on its side at the top.

If your angelfish is floating on its side at the top, first assess and improve water quality by checking and adjusting the levels of ammonia, nitrites, nitrates, and pH.

Next, evaluate the fish’s diet and feeding schedule, potentially incorporating easy-to-digest foods like cooked peas to alleviate swim bladder issues.

Finally, observe for any signs of disease or stress, and consider isolating the fish for specific treatment, such as anti-parasitic or antibiotic medications, based on the symptoms observed.

Also Read: Why Is My Angelfish Not Moving?


For quick readers, here’s a short summary:

  • Angelfish lying on their side signals distress or illness, often caused by swim bladder disorder, poor water quality, or infections, and requires immediate action.
  • The main reasons include swim bladder disorder from overfeeding, water quality issues like high ammonia, and health problems such as parasitic and bacterial infections.
  • Remedies involve adjusting diet, enhancing water quality, using specific medications for parasites or bacteria, and caring for physical injuries.
  • Recovery chances for angelfish depend on prompt and accurate treatment of the cause, consistent care, and maintaining an ideal tank environment.
  • An angelfish floating sideways at the tank’s top usually suffers from severe swim bladder disorder or stress, needing urgent water quality checks and treatment.