Why Is My Pleco Fish Shaking? (5 Practical Solutions)

Disclosure: When you purchase something through my affiliate links, I earn a small commission. As an Amazon Associate, I earn from qualifying purchases.

Taking care of Plecos is pretty straightforward, as they are calm fish that don’t require that much attention. However, from time to time, they do show worrying signs.

For example, a couple of months back, I noticed that one of my Plecos was twitching consistently and scratching against the aquarium objects.

Why do Plecos shake? Does it mean trouble? What steps can you take to stop this from happening? Are some Plecos species more prone to this behavior than others?

In this article, I’ll discuss all these questions and more so that you leave with all the information you need. Let’s get started.

Is Twitching in Plecos Normal?

No, twitching in Plecos is not typical behavior. Consistent twitching can often suggest underlying problems with the fish or its environment.

  • Rare Occurrence: In a healthy aquarium setting, Plecos typically display smooth, deliberate movements rather than erratic twitches.
  • Mismatch with Natural Behavior: In the wild, Plecos are known for their steady grazing and clinging activities; twitching can indicate a departure from this norm.
  • Indication of Distress: Twitching can be a Pleco’s way of signaling discomfort or distress in its current environment.
  • Potential Health Issues: Healthy Plecos should exhibit consistent, calm behavior; twitching might hint at diseases, infections, or other health-related concerns.

Why Is My Pleco Shaking?

There could be a few reasons for shaking in Plecos. Let’s dive into the common culprits:

1. Stress

Just like other fish, Plecos can experience stress due to a variety of reasons in the tank.

  • Water Parameters: Plecos are sensitive to water changes. Any sudden shifts in pH, temperature, or nitrate levels can cause them stress.
  • Tank Mates: If Plecos are housed with aggressive fish or overpopulated tanks, they might display shaking as a sign of stress.
  • Inadequate Shelter: Plecos love hiding spots. Without proper caves or hiding places, they may feel exposed and stressed.

Also Read: Stress In Pleco Fish

2. Breeding Behavior

Sometimes, the shaking is a sign of mating rituals and not a cause for alarm.

  • Mating Dance: Male Plecos often shake to attract females or assert dominance during breeding times.
  • Spawning Grounds: If you observe shaking near a chosen nesting spot, it might be related to breeding activity.
  • Competitive Behavior: Male Plecos might shake to warn other males to stay away from their territory during breeding seasons.

3. Disease or Parasites

Shaking can be a sign of health issues ranging from infections to external parasites.

  • Visible Signs: Look for other symptoms like white spots, cloudy eyes, or clamped fins. These often accompany diseases in Plecos.
  • Loss of Appetite: If your Pleco is shaking and not eating, it might be battling an internal infection or parasite.
  • Unusual Movement: Plecos infested with parasites might scratch against tank decorations or show rapid gill movement alongside shaking.

4. Water Quality Issues

The quality and consistency of the water in an aquarium are vital for the well-being of Plecos.

  • Chemical Imbalance: Plecos can become agitated when exposed to high ammonia, nitrite, or nitrate levels. Regular water tests can help you monitor this.
  • Infrequent Water Changes: Plecos thrive in clean water. Infrequent water changes can lead to a buildup of toxins, causing discomfort.
  • Inadequate Filtration: A filter that’s too small or not efficient can lead to poor water quality, making Plecos shake or twitch.

5. External Irritants

Sometimes, factors outside the fish tank can distress Plecos.

  • Loud Noises: Sudden loud noises, like those from construction or heavy machinery, can be jarring for Plecos and induce shaking.
  • Bright Lights: If the tank is exposed to direct sunlight or strong artificial lights without a break, it can stress Plecos.
  • Vibrations: Plecos can feel and get stressed by vibrations from nearby devices or activities, such as a running washing machine or other household equipment.

How to Treat Plecos That Consistently Twitch

Let’s address each of the possible causes of twitching in plecos:

1. Addressing Breeding Behavior

Breeding rituals can cause twitching, and there are steps to make the process smoother for Plecos.

  • Provide Caves: Offering several clay or PVC caves, about 1-2 inches in diameter, can give males spaces to attract females. I personally picked this Jabukosu Aquarium Cave (link to Amazon).
  • Increase Tank Size: For breeding, a tank of at least 50-75 gallons ensures ample space, reducing territorial disputes.
  • Separation: Consider dividing aggressive breeders or over-enthusiastic males using tank dividers or separate tanks.
  • Monitor Behavior: Keep a keen eye during breeding seasons; sometimes, simply reducing the number of males can alleviate tensions.

Also Read: Breeding Pleco Fish

2. Stress Management

Reducing stress is crucial for the overall health of Plecos.

  • Acclimate Slowly: When introducing Plecos, gradually adjust them to tank conditions over 1-2 hours to reduce shock.
  • Hideouts: Add natural driftwood or plants, ensuring Plecos have quiet, shaded spots to retreat to.
  • Consistent Parameters: Use a reliable aquarium test kit; maintain pH between 6.5-7.5 and temperatures around 76-80°F. I use the well-known API Freshwater Master Test Kit (link to Amazon).
  • Limit Disturbances: Keep the tank in a quieter part of your home, away from frequent foot traffic or noisy appliances.

Also Read: Do Plecos Need Hiding Spots?

3. Disease or Parasite Control

Treating diseases or parasites promptly ensures Plecos remain healthy.

  • Quarantine New Fish: Always isolate newcomers for 2-3 weeks, observing for signs of diseases or parasites.
  • Anti-parasitic Treatment: For suspected infections, medications like Fritz Mardel Coppersafe (link to Amazon) can be effective for Plecos.
  • Regular Observations: Look out for white spots, cloudy eyes, or irregular poop – early detection can lead to more successful treatments.
  • Maintain Cleanliness: Perform 25-30% water changes weekly and siphon the substrate to prevent disease outbreaks.

Also Read: Pleco Fish Diseases

4. Improving Water Quality

Good water quality is paramount for the health and comfort of Plecos.

  • Regular Testing: Utilize a comprehensive test kit bi-weekly to monitor ammonia, nitrite, nitrate, pH, and hardness levels, aiming for optimal conditions.
  • High-Quality Filter: Invest in a powerful filter that can handle the tank’s volume, cycling it 4-5 times per hour to ensure clean water.
  • Natural Additives: Consider using driftwood or almond leaves; they release tannins which can benefit Plecos by simulating their natural environment. My Plecos love this Dr. Moss Malaysian Driftwood (link to Amazon).
  • Dissolved Oxygen: Ensure adequate oxygen levels with a good balance of plants and aeration, using air stones or bubblers if necessary.

Also Read: Do Plecos Need A Bubbler?

5. Minimizing External Irritants

External factors can significantly influence the behavior of Plecos in an aquarium.

  • Controlled Lighting: Limit direct sunlight, and provide a consistent light schedule with 10-12 hours of light daily using aquarium-specific lighting.
  • Soundproofing: Place the aquarium away from high traffic areas, and consider using soft mats underneath to dampen vibrations.
  • Chemical Avoidance: Be cautious with household cleaners or sprays near the tank; even minor exposure can stress or harm Plecos.
  • Regular Observation: Be mindful of sudden changes in behavior after introducing new equipment, decorations, or after rearrangements in the room, and adjust accordingly.

Are Some Pleco Species More Likely to Shake Than Others?

Yes, some Pleco species are indeed more predisposed to certain behaviors, including shaking, than others.

The degree of such behaviors often depends on their native habitats, specific needs, and adaptability.

  • Sensitive Species: The Zebra Pleco (L046) is known for its sensitivity to water conditions. Any slight imbalance can induce stress and resultant shaking.
  • Territorial Types: The Sultan Pleco (L264) is highly territorial, especially during breeding. Any perceived threat or encroachment might trigger shaking or twitching behaviors.
  • Large Varieties: The Common Pleco, which can grow up to 24 inches, requires ample space. In smaller tanks, confinement can lead to stress and related behaviors.
  • Adaptable Species: The Clown Pleco (Panaqolus maccus) is a hardy variety that’s more adaptable to different water conditions, making it less prone to stress-induced shaking compared to others.
  • Specialty Plecos: The Blue-eyed Pleco (Panaque suttonorum) comes from colder mountain streams. If not provided cooler water, they might exhibit discomfort through shaking.

Also Read: Why Is My Pleco Breathing Fast?

Zebra Pleco

How to Prevent Plecos from Shaking in the Future

Preventing your Plecos from shaking in the future is a matter of understanding their needs and being proactive in your aquarium management.

Consistent care and keen observation can keep them comfortable and at ease.

  • Optimal Water Conditions: Regularly test the water, ensuring ammonia and nitrite are at 0 ppm, while maintaining a pH level between 6.5 and 7.5 for Plecos.
  • Scheduled Light Patterns: Plecos appreciate consistency; aim for 10-12 hours of aquarium-specific lighting daily, avoiding direct exposure to sunlight.
  • Balanced Diet: Feed your Plecos a mix of algae wafers, fresh vegetables (like zucchini), and occasional protein treats to keep them well-nourished and stress-free.
  • Quarantine Practices: Any new addition to your tank should be isolated for 2-3 weeks. This helps prevent potential diseases or parasites from affecting your existing Plecos.
  • Stable Environment: Limit abrupt changes; if adjusting water temperature, aim for no more than 2°F per hour. Plecos thrive in stable conditions, reducing the likelihood of stress-induced shaking.

Also Read: Why Is My Pleco Swimming Erratically?


For quick readers, here’s a short recap:

  • Twitching in Plecos isn’t typical and can indicate distress, potential health issues, or problems with their environment.
  • Common reasons for Pleco shaking include stress from water conditions, breeding behaviors, diseases/parasites, water quality issues, and external irritants.
  • To address twitching in Plecos, one can provide breeding caves, manage stress by maintaining consistent water parameters, treat diseases promptly, ensure high water quality, and minimize external disturbances.
  • Preventing Pleco shaking involves maintaining optimal water conditions, consistent lighting schedules, a balanced diet, strict quarantine practices for new fish, and ensuring a stable tank environment.
  • Observing and understanding Pleco needs, coupled with proactive aquarium management, is key to keeping them comfortable and preventing twitching in the future.