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5 Clear Signs Your Pleco Is Dying

5 Clear Signs Your Pleco Is Dying

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The purpose of this blog is to share general information and is written to the author's best knowledge. It is not intended to be used in place of veterinary advice. For health concerns, please seek proper veterinary care. In addition, as an Amazon Associate I earn from qualifying purchases.

Plecos are wonderful beginner-friendly fish. They’re hardy, relatively low-maintenance, and can thrive for decades under captivity.

Plus, some species—like Zebra Plecos and Typhoon Plecos—are insanely beautiful, so much so that they’re considered a collector’s fish.

Although plecos are easy to take care of, they’re not immune to sickness, disease, and old age. This article discusses all the signs your pleco is dying and what to do to prevent it.

1 – Loss of Color

Light Pleco Dead in the Corner of a Holding Tank

If your pleco is losing its color and slowly turning white, this might be an indication that it’s either sick or dying. Your pleco needs immediate care in both cases.

Plecos turn white for a variety of reasons, including, but not limited to: poor nutrition, disease, stress, or inadequate tank conditions.

Let’s discuss each of these possibilities in more detail.

Poor Nutrition

Although plecos mostly eat algae, they require other food, too.

Plecos are omnivores, so they need to be fed a well-rounded diet that includes both protein and vegetables. Without proper nutrition, plecos are likely to starve to death.

There are over 100 different species of plecos, so it’s always a good idea to consult your vet or look up the species to learn what’s best to feed them.

Most plecos eat tablet and disc foods, as well as vegetables like kale, cabbage, zucchini, and shelled peas.

Make sure to feed your plecos at least two times a week at night.


Pleco Searching for Food in Rocks on Bottom of Tank

Stress is one of the deadliest killers of pet fish.

If your pleco is overly stressed and you don’t do anything about it, it’ll likely die within a few days, weeks, or months.

Symptoms of stress in plecos include the following:

  • Color fading
  • Hiding
  • Glass surfing
  • Weight loss
  • Decreased appetite
  • Odd swimming patterns

Stress occurs for a number of reasons, including temperature fluctuations, aggressive tank mates, underfeeding, and wrong pH levels. Identify the source of the problem and see what you can do about it.

For instance, if you believe the source of your pleco’s stress is caused by aggressive tank mates, separate the pleco into a different tank. Then, give your plecos enough hiding spots or redesign the tank to reduce aggression.

Improper Tank Conditions

Like most fish, plecos also have specific tank environment needs. Plecos are freshwater fish, so you shouldn’t ever place them amongst saltwater fish.

The water needs to be at a pH level of 7.0 to 8.0 and alkalinity between 3° and 10° dKH. This is about 54 to 180 ppm.

If your pleco is wild-caught, it requires a pH level of 5.5 to 7.0 and alkalinity below 3° dKH (54 ppm). You can test your water’s pH and alkalinity with a water test kit.

Water temperature is just as important as pH and alkalinity. Most plecos prefer temperatures between 72 to 78°F, but they’re tolerant of water conditions ranging from 65 to 85°F.

Temperatures in the high 50s might be okay for a while, but it needs to be corrected as soon as possible lest the fish die of stress or disease.

Likewise, adult common plecos need to be placed in a tank of at least 150 gallons. For other species, here are the minimum required tank sizes:

  • Sailfin and royal plecos: 125 gallons
  • Gold nugget plecos: 50 gallons
  • Zebra, clown, and snowball plecos: 30 gallons
  • Bristlenose plecos: 25 gallons

2 – Spots or Fungus on Gills, Fins, or Body

Snakeskin Barb With Ich Spots

If you notice white spots on your pleco’s body, this might be a sign of ich.

Ich, also known as white spot disease, is among the most common health conditions found in tropical-fish aquariums, which most plecos inhabit. It’s a disease in which a parasite attaches itself to the pleco’s fins, gills, or body, where it feeds until maturity.

If a pleco has ich, you’ll notice tiny, salt-like crystals or “spots” all over its body. Ich is highly contagious and, if not treated immediately, might prove to be fatal.

Luckily, ich is relatively easy to take care of. Simply quarantine the affected fish and use commercial ich remedy for at least two weeks until the fish is completely treated.

Of course, always consult a veterinarian first before administering any kind of medication for your pleco.

3 – Abdominal Swelling

Fantail Goldfish with Dropsy, Or a Swollen Belly

Unlike ich, dropsy is a symptom of an underlying disease (i.e., parasitic infections, bacterial infections, or liver dysfunction).

It’s characterized by the swelling of soft tissues due to fluid build-up inside the fish’s body cavity or tissues.

Plecos who have this condition often have hugely swollen bellies, as if bloated, and bulging eyes.

Here are some other symptoms to look out for:

  • Pale gills
  • Red and/or swollen anus
  • Pale and stringy feces
  • Abnormally curved spine
  • Inflamed or discolored skin or fins
  • Fins clamped to the sides
  • Swimming near the surface
  • Lethargy

4 – Cloudy Eyes

If your pleco appears to have cloudy eyes (i.e., eyes covered with whitish/gray slime), this might be a sign of an underlying disease or injury that may or may not be deadly.

The major causes of cloudy eye disease include injury, infection, and poor water quality. Once you rule out the possibility of poor water quality, consult a veterinarian so he/she can help you treat your fish.

5 – Rotting or Fraying Fins

Patriot Betta With Fin Rot

Fin rot is a condition caused by bacterial and/or fungal infection. Usually, this results from injury, bad diet, poor water conditions, or secondary infection.

When not treated immediately, the disease may advance to a stage called fin and body rot, wherein the infection starts attacking the fish’s body. Unfortunately, fin and body rot is usually fatal.

If you notice your pleco suffering from fin rot, change the tank’s water and check the filter. Make sure everything is in optimal condition.

Then, consult a veterinarian so he/she can prescribe the right antibiotics or antifungal medication for your pleco.

Final Thoughts

Known to eat almost anything, plecos are hardy fish that live up to 10 to 15 years.

If your pleco isn’t as active as it used to be or shows any of the symptoms mentioned above, this might be a sign that your pleco is sick or dying.

Poor water quality, insufficient nutrition, stress, and disease are the biggest causes of pleco death, so make sure your aquarium is in tip-top condition to prevent these issues.

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Friday 25th of February 2022

His fins look to be different an he has I believe a blister from running into the glass walls.


Friday 25th of February 2022

My pleco look sick an he's not active at all. An I haven't seen him eat in 2 days I gave him wafers an he not eating that. I changed my water yeasterday nrw filter. He stays in the same spot. He won't swim or nothing can u help