Do Plecostomus Shed Their Skin? {The Real Truth Finally Revealed}

Is your Plecostomus getting dry or slimy? Do you see any skin peeling off or excess gunk on the body of your Plecostomus? In this article, we’ll find if Plecostomus really shed their skin.

Do Plecostomus Shed Their Skin? No. If your Plecostomus is showing dry peeling skin or dry spots falling off, there is an issue with Ich or a fungal infection. If you see excess slime, then we can say that a Plecostomus builds up and releases some of its slime coating through growth spurts or poor water conditions. 

Why Is My Plecostomus Shedding Its Skin?

The word “shedding” becomes the topic of debate when discussing the plecostomus, commonly referred to as a pleco. We have to look closer at what’s going on. Let’s separate this topic into two parts:

  • dry skin
  • slimy skin

Dry Skin

Although the skin or scales on aquarium fish contain the slime coating for their own protection, we may notice peeling or drying of the skin when shedding occurs. Does the plecostomus actually do this?

The clear answer is no. If you see this happening, it’s the drying of a fungal growth or the maturing and dropping of Ich protozoans.

Slimy Skin

Does it look like someone dropped a bunch of goop or gunk on your plecostomus? The excess slime coating could be “shedding” like a film coating slowly slipping off its body.

If you see your plecostomus maintaining its position in front of a current, the slime could slip off much faster.

Why Is My Plecostomus Shedding Its Slim Coat?

Sometimes a malnourished plecostomus could be seen sucking on the slime coat of other fish. This is not the same as building up excess slime, but malnourishment could play a factor in both cases.

These are the three main reasons why your plecostomus is shedding its slime coat:

  1. Lack of nutrients
  2. Poor water quality 
  3. Growth spurt

Is My Pleco Building Excess Slime From Malnutrition?

The excess slime could result from lack of nutrients. Plecos needs a sufficient amount of algae in the wild to survive. Plecos are omnivores and opportunistic scavengers in the wild. They’ll eat anything that comes their way.

We have to substitute wild algae growth for vegetables and sinking proteins that your plecostomus will devour with time, training and patience. Depending on debris, leftovers, diatoms and algae in your tank will not cut it.

Pleco specific food is available at your local fish shop, but the vegetables are yours to play around with. Make sure to clip them, weigh them down or tie them at the bottom of the tank for your plecos to learn that it’s for them to enjoy.

Try these foods every other day:

  • algae wafers
  • zucchini
  • squash
  • cucumber
  • bloodworms
  • brine shrimp
  • sinking pellets 
YouTube video

Does Water Quality Cause Plecos To Shed Their Skin?

We simply cannot state that plecostomus shed their skin. It’s a slime coating that gets thick or extra slimy. This excess film could occur when the water quality is not optimal. Run a water test to see if you get results within these parameters:

  • Water Temperature: 74-80° F
  • pH: 7.0-8.0
  • Alkalinity: 3-10° dKH (54 ppm to 180 ppm)
  • Nitrates: Less than 40 ppm
  • Nitrites and Ammonia: 0 ppm

This is a bad slime coat reaction if the water quality is poor. Make sure the nitrogen cycle isn’t off and consider using a conditioner to keep your water levels from spiking. Increase water changes and observe the skin of your plecostomus to notice any difference.

Is My Pleco Shedding Because Its Growing?

The slime coat on a plecostomus will build up and release during growth spurts. It may seem like they are shedding their skin, but it’s what on the skin that is slipping off.

If the current is stronger in your tank, you may notice it happening in front of your eyes. If not, you may see a buildup of slime around the bottom of the tank that came from your pleco. The slime coat on a plecostomus gets heavier as they grow. This is most likely what you are noticing.

The Skin On My Pleco Is Peeling. Is This Normal?

No, it is not normal for the skin of a plecostomus to be peeling. What you are seeing is probably a fungal infection on the body of your pleco. A fungal growth is not the same as a parasitic infection like Ich. Both conditions show up on the skin and eventually fall off.

Fungal growths can get larger and spread across the body in patches. Look to treat fungal infections or Ich with the following:

  • specific medications for either Ich or a fungus
  • raise the water temperature
  • 1 tablespoon of aquarium salt per 5 gallons of water
  • consult with a professional

We cannot diagnose your plecostomus from here. We always advise seeking the input from a professional who has either seen your plecostomus in person or a high quality picture of the skin shedding that you are seeing.

Is My Plecostomus Shedding Because Its Stressed?

Your plecostomus may end up building up more slime on its body in times of stress. The reasons for stress are due to various factors. Sometimes it’s a combination of these three causes below:

  • aggressive tankmates
  • small tank size
  • lack of hiding spaces


A plecostomus is a great addition to a community tank with ideal tankmates such as:

  • Guppy Fish
  • Molly Fish
  • Platy Fish
  • Swordtail Fish
  • Cory Catfish
  • Dwarf Gourami Fish
  • Betta Fish

Aggression is not tolerated well by a peaceful pleco. Consider removing the aggressors or try a larger tank.

Tank Size

If the tank is under 50-100 gallons for a 15 ich pleco, stress is sure to build up. A slime coating that looks like its being shed may result. A pleco in a smaller tank has a higher risk of injury and illness as well.

Hiding Spaces

Your plecostomus will be calmer and much less stressed if you build a tank setup where they are given the space to hide and test. The hiding may not be out of fear.

This is a fish that enjoys the dark. The shade you provide could boost the immune system and eliminate excess slime from building up and releasing into your tank.


The debate about whether or not a plecostomus actually sheds its skin continues in forums and threads. They usually end in agreement when deciding that the slime coating is what is actually being shed. Can slime shed?

Imagine a film coating that slips off, but a thicker coat replaces it with age and growth. Fungal growths or Ich may look like shedding, but it’s actually worse and needs treatment.


We hope this article sheds light on this topic, but allows you to observe more carefully at the current condition of slime or skin falling off your plecostomus. Thanks for visiting and see you again soon!

Brian Arial

Brian Arial has kept fish for leisure and worked with fish stores for most of his life. He enjoys writing and caring for aquariums and ponds.

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