Why Is My Pleco Floating At The Top? (5 Easy Solutions)

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I’ll always remember the time I noticed my Pleco fish hovering near the surface of the tank. It was alive, but its unusual posture and labored breathing left me concerned.

At first, I was puzzled about what was going on and how to handle it. The thought of losing my fish was distressing.

But, a quick online search came to my aid and made all the difference for my Pleco.

In this article, I’ll guide you through the reasons why Pleco fish might be found near the tank’s surface, how to address the situation, and measures to ensure it doesn’t recur.

Let’s get started.

Why Is My Pleco Floating at the Top?

Your Pleco is probably floating at the top due to a swim bladder disorder, which affects its buoyancy.

This condition is relatively common and can have various causes, making the fish struggle to maintain its position in the water.

  • Swim Bladder Basics: Plecos possess a swim bladder for buoyancy. If impaired, they struggle to stay submerged.
  • Dietary Causes: Overfeeding or unsuitable foods can lead to issues. Dry pellets, for instance, can be a culprit when not soaked.
  • Water Quality: Poor conditions can stress Plecos. It’s vital to consistently monitor pH, ammonia, and nitrate levels.
  • Bacterial Infections: Plecos can get infections affecting the bladder. This can arise from injuries or an unclean tank.

Also Read: Pleco Fish Swim Bladder Disorder

What Causes Swim Bladder Issues in Plecos?

Swim bladder disorder in Plecos arises from a variety of factors:

1. Suboptimal Water Conditions

Maintaining a stable environment is crucial for Plecos. When water conditions are suboptimal, it can lead to various health issues, including swim bladder problems.

  • Ammonia Spikes: Elevated ammonia levels can be particularly harmful to Plecos. Prolonged exposure can damage organs, impacting the swim bladder’s function.
  • Temperature Fluctuations: Plecos need consistent water temperatures. Rapid or frequent changes in the tank’s temperature can cause undue stress and health concerns.
  • Incorrect pH Levels: It’s vital to ensure the right pH balance for Plecos. A shift outside their preferred range can significantly disrupt their metabolic processes.

2. Excessive Feeding

Diet plays a pivotal role in a Pleco’s health. Overfeeding or offering inappropriate foods can lead to digestion-related and buoyancy issues.

  • Gas Production: Some foods, when digested, lead to excessive gas production in Plecos. This can cause the swim bladder to expand, altering buoyancy.
  • Dry Foods: Feeding Plecos unsaturated dry foods can be a problem. Ingesting excess air with these foods might trigger swim bladder disturbances.
  • Digestive Blockages: Excessive consumption can cause blockages in Plecos. This puts undue pressure on the swim bladder, impacting buoyancy.

3. Disease and Infections

Disease outbreaks can have a profound effect on Plecos. Swim bladder-related issues often arise from various infections or diseases.

  • Bacterial Infections: Bacterial invaders can cause inflammation in the swim bladder. This makes buoyancy regulation challenging for Plecos.
  • Parasitic Invasions: Some parasites can target the swim bladder or neighboring organs. When this occurs, Plecos may struggle to maintain their preferred depth.
  • Viral Causes: Certain viruses, though less common, can hinder the swim bladder’s operation, hampering a Pleco’s ability to float or sink.

4. Physical Injuries

Physical traumas, often unintentional, can be detrimental to Plecos. Injuries to the swim bladder or its vicinity can lead to buoyancy irregularities.

  • Tank Decor: Sharp or rough tank decorations can pose threats to Plecos. Unintended injuries might damage their internal organs, including the swim bladder.
  • Aggressive Tank Mates: Some cohabitating fish might show aggression towards Plecos. Resulting injuries can adversely affect the swim bladder’s function.
  • Handling Injuries: During tank maintenance or transfers, Plecos can be mishandled. Such episodes can cause harm to their internal structures.

5. Hereditary Factors

Genetics can play a part in a Pleco’s overall health. Some may have inherent susceptibilities to swim bladder complications.

  • Inbreeding: Limited genetic diversity in certain Pleco breeds can lead to inherent health issues. Swim bladder disorders might be more prevalent in such cases.
  • Natural Buoyancy Variations: There are Plecos with naturally varying swim bladder structures. Such genetic variations can influence their buoyancy.
  • Developmental Issues: As some Plecos age, genetic factors can surface, presenting challenges in buoyancy regulation.

How Can You Treat a Pleco With Swim Bladder Problems?

To help a floating Pleco fish with a swim bladder disorder, follow these steps based on the underlying cause.

1. Enhance Water Conditions

Creating the right aquatic environment is vital. Consistently maintaining top-notch water conditions can make a significant difference for Plecos.

  • Weekly Water Changes: Regularly change 25% of the tank’s water. Using dechlorinated water helps eliminate toxins and maintains clarity. I use the Tetra AquaSafe (link to Amazon) for that.
  • Temperature Control: Use heaters and coolers to keep a precise 76°F (24°C). Consistency is key; sudden changes can distress Plecos.
  • Regular pH Testing: Aim for 6.8 pH. Using pH adjusters or natural peat can help maintain this acidic-alkaline balance.
  • Ammonia and Nitrate Check: Employ accurate test kits to ensure ammonia is always 0 ppm and nitrates remain below 20 ppm for Pleco health. My recommendation: API Freshwater Master Test Kit (link to Amazon).

2. Monitor Feeding Habits

Diet is integral to a Pleco’s well-being. Proper feeding habits can alleviate or prevent swim bladder issues.

  • Limit Dry Food: Pre-soak pellets for 10 minutes. This ensures Plecos don’t ingest excess air, reducing buoyancy problems.
  • Offer Greens: Twice a week, add sliced cucumber or boiled zucchini. Plecos adore them, and they assist in digestion.
  • Feeding Frequency: Give Plecos a diet consisting of 2% of their body weight daily, ensuring consumption within 3 minutes.
  • Diversify Diet: Alternate between algae wafers, blanched spinach, and bloodworms to ensure Plecos get varied nutrients. I personally use these Invert Aquatics Mini Algae Discs (link to Amazon).

3. Address Diseases and Infections

Proactive care is essential. Treating diseases promptly can prevent them from exacerbating swim bladder issues.

  • Quarantine New Fish: Use a 10-gallon quarantine tank, treating newcomers for 3 weeks, reducing the risk of introducing pathogens.
  • Medication: When symptoms show, dose with antibiotics like Kanamycin or Metronidazole, following manufacturer guidelines strictly.
  • Professional Diagnosis: Secure annual check-ups with an aquatic vet to monitor the health and well-being of your Pleco.
  • Salt Baths: Using a 1% salt solution (10 grams per liter), submerge Plecos briefly to treat minor infections; monitor closely.

4. Tend to Physical Injuries

Attending to injuries promptly prevents complications. Plecos, being delicate, need special attention in such scenarios.

  • Safe Environment: Opt for soft-edged decorations, ensuring a Pleco-friendly environment that minimizes injury risks.
  • Separation: If bullying occurs, use tank dividers or separate tanks to isolate the injured or aggressive parties temporarily.
  • Gentle Handling: Use a soft mesh net or a container to move Plecos; rough nets can cause scale damage or stress.
  • Antiseptic Treatments: For minor wounds, a diluted Methylene Blue bath (5 ml per 10 liters) can assist; always monitor reactions.

5. Recognize Hereditary Factors

Some Plecos inherently face challenges. Knowing this aids in care and sets correct expectations.

  • Research Pleco Breed: Familiarize yourself with specific breeds like the L046 Zebra; some have known genetic buoyancy issues.
  • Symptom Management: For congenital issues, adjust diet and environment, ensuring the Pleco’s maximum comfort and minimal stress.
  • Avoid Inbreeding: When breeding, cross with different Pleco lineages, increasing genetic diversity and health probabilities.
  • Consult Experts: Engage in forums like PlanetCatfish, seeking breed-specific advice or shared experiences to aid your Pleco’s care.

What’s the Outlook for Plecos with Swim Bladder Disorder?

The outlook for Plecos with swim bladder disorder can vary based on the severity and the timely intervention provided.

With appropriate care and attention, many Plecos can either recover or manage the condition with minimal discomfort.

  • Initial Stages: If detected early, most Plecos with mild symptoms can see improvements within a week with proper care.
  • Severity Matters: Severe cases, where Plecos float upside-down or can’t submerge, might need extended treatment and may have prolonged recovery periods.
  • Treatment Timeframe: On average, with prompt intervention, Plecos can show signs of recovery in 2-4 weeks, depending on the issue’s cause.
  • Chronic Cases: Some Plecos might have chronic swim bladder issues due to genetic factors, requiring continuous care and symptom management.

Also Read: Why Is My Pleco Floating Upside Down?

How Can You Prevent Swim Bladder Issues in Plecos?

Preventing swim bladder issues in Plecos is far more effective than treating them.

By ensuring an optimal environment and monitoring dietary habits, the risks associated with swim bladder disorders can be minimized.

  • Regular Water Testing: Weekly checks of ammonia, nitrate, and pH levels can maintain an optimal environment for Plecos, preventing stress.
  • Dietary Management: Feeding a mix of soaked pellets, vegetables, and live foods ensures a balanced diet, reducing digestive complications for Plecos.
  • Avoid Rapid Changes: Sudden shifts in water temperature or parameters can distress Plecos; aim for gradual adjustments over several days.
  • Tank Setup: Using fine-gravel or sand substrates with no sharp decorations can reduce the risk of Plecos injuring themselves.
  • Observation: Spend 10-15 minutes daily observing Pleco behavior. Early detection of abnormalities can be the key to preventing severe swim bladder issues.

What Might Be Other Reasons for Plecos Floating?

In addition to a swim bladder disorder, two other potential reasons for a Pleco fish floating at the surface are:

1. Lack of Adequate Oxygen

Just like other fish, Plecos rely on oxygen dissolved in the water to breathe. If the oxygen levels in the tank are too low, your Pleco might float to the surface trying to get more air.

  • Observation: Plecos gasping at the water surface or showing rapid gill movement indicates they’re trying to get more oxygen.
  • Causes: Overstocked tanks or poor water circulation can lead to reduced oxygen levels, making it hard for Plecos to breathe.
  • Effects: Extended exposure to low oxygen can stress Plecos, leading to weakened immunity and susceptibility to diseases.
  • Solution: Increase aeration using air stones or upgrading to a more powerful filter. I personally picked the Hygger Aquarium Air Stone (link to Amazon). Regular water changes can also boost oxygen levels.

2. Your Pleco Might Have Passed Away

It’s a sad reality, but like all living creatures, Plecos have a finite lifespan, and they might float when they pass away.

  • Observation: A Pleco that doesn’t react to stimuli and stays afloat for extended periods might have unfortunately died.
  • Natural Causes: Old age, or underlying health issues, can be factors when a Pleco’s life comes to its natural end.
  • External Factors: Improper tank conditions, aggressive tank mates, or untreated diseases can lead to premature death.
  • Solution: Regular health checks, ensuring proper water parameters, and providing a safe environment can extend your Pleco’s lifespan.

3. Your Pleco Could Be Scouring for Food

Sometimes, floating isn’t a sign of distress. Plecos, being opportunistic feeders, might float near the surface, looking for food morsels.

  • Observation: If your Pleco occasionally floats and seems alert, it might simply be exploring or searching for food.
  • Natural Behavior: Plecos have been observed eating floating plants or catching floating food particles in natural habitats.
  • Effects: This behavior isn’t necessarily harmful but indicates that the Pleco might be feeling hungry or lacks certain nutrients.
  • Solution: Ensure a balanced diet with a mix of sinking wafers, vegetables, and occasional protein sources to keep your Pleco satiated and nutritionally balanced.


For quick readers, here’s a short recap:

  • Plecos floating at the top often have a swim bladder disorder affecting their buoyancy, caused by factors like diet, water quality, bacterial infections, and more.
  • Pleco’s swim bladder issues can arise from suboptimal water conditions, excessive feeding, diseases and infections, physical injuries, and hereditary factors.
  • To treat a Pleco with swim bladder problems, enhance water conditions, monitor feeding habits, address diseases and infections, tend to physical injuries, and recognize hereditary factors.
  • The outlook for Plecos with swim bladder disorder varies based on severity and intervention, but with proper care, many can recover or manage the condition.
  • Prevention strategies include regular water testing, dietary management, avoiding rapid changes, proper tank setup, and daily observation.