7 Signs Your Pleco is Dying and How to Treat

Plecostomus fish, commonly called “plecos”, are relatively easy to take care of. However, like any fish, they can develop sickness too. Therefore, it is important to notice your fish’s behaviors when they become sick.

Loss of color, rotting fins, and white spots on its body are some of the common signs that a pleco might be dying. 

This could happen to any fish owner, so it is essential to understand the causes of these symptoms and how to treat them.

Read on to learn about the signs and symptoms, the causes, and treatment options for your pleco.

---

7 signs of a dying pleco

There are common signs and symptoms among fish diseases that show your fish is battling more than just a common sickness. 

Signs and symptoms	Causes	How to treat
Loss of color/turning white	-Poor tank conditions -Stress -Poor nutrition	-Research nutrition based on specific pleco species -Check water levels, adjust accordingly
Rotting fins	-Poor water conditions -Bacterial infection -Stress	-Maracyn Two treatment  -Check water levels, adjust accordingly
Spots on the body (Ich)	-Poor water conditions -Stress	-Ich treatment-Isolation
Abdominal swelling	-Poor water conditions -Internal infection -Constipation	-Feeding high-fiber foods -Isolation -Fix harmful tank conditions
Cloudy eyes	-Poor water conditions -Injury -Stress	-Isolation -Fixing the cause (poor water conditions, stress, etc.)
Pop eye	-Poor water conditions -Injury -Bacterial infection	-Check water conditions -Isolation -Consult vet
Laying on its side/Lethargy	-Poor water conditions	-Check water conditions -Fix problem with water changes

#1 Loss of color

If your fish is showing a loss of color or turning white, this may be a sign your pleco is dying. This can be caused by many things, such as poor water conditions, stress, or poor nutrition. 

Since plecos are a type of catfish, they feed off of algae. However, they still require feeding two times a week to have a balanced diet.

Monitor your fish’s feeding to ensure he is eating. There are over 100 species of plecos, so it is essential to do your research to learn the best source of nutrition for your pleco species. 

Plecos living in an environment with other fish could also be stressed. Rapid temperature changes, irregular feeding schedules, and poor water conditions also contribute to stress in fish.

If your fish is stressed, you may notice the loss of color in addition to the loss of appetite and abnormal swimming behaviors. Your pleco may also be stressed due to their tank mates.

Aggression in fish leads to erratic swimming and crashing into the tank. You may also notice your pleco laying at the bottom of the tank or chasing the other fish around.

Plecos live in environments with temperatures between 72 and 78 degrees Fahrenheit. Checking temperature and pH levels is also essential because the water needs to be at a pH of 7.0 to 8.0.

If your temperature and pH are out of this range, you need to take steps to remedy the situation.

#2 Rotting fins

Fin rot is caused by underlying conditions such as bacterial infection. Poor water conditions usually cause bacterial infections.

If your pleco’s fins start to rot or decay, it is important to act quickly as this can spread to the fish’s body. If this is not taken care of, it will cause your fish to die.

The signs your fish’s fins are rotting:

• fin edges turn black or brown and look frayed
• have white dots (another possible symptom of ich)
• falling off in large chunks

Fin rot is one of the most preventable illnesses, as the main contributor to this disease is poor water conditions. Monitoring your water levels and performing weekly water changes will prevent this from happening to your fish.

#3 Spots on body/Ich

White spots may appear on your fish if it is sick. This disease is called “ich” (Ichthyophthirius multifiliis) and can be fatal if not treated. It is the most common disease in tropical fish, like plecos, and is likely caused by poor water conditions.

Ich is very contagious and can be fatal, so removing the sick fish from the tank is important if other fish inhabit the same environment. Your fish may be suffering from ich if their skin appears to have white dots that look like salt or sugar flakes.

We have a separate article all about Ichthyophthirius multifiliis (Ich), so be sure to check it out.

Like fin rot, Ich may appear due to poor tank conditions. Checking and monitoring the levels, temperature and pH will ensure the tank has the proper conditions for your pleco.

Increasing the temperature in the sick fish’s tank is another way to combat the disease and aid recovery. It creates an environment where the disease cannot grow or spread. Quarantining and giving medicine is the most effective way to cure this disease.

#4 Abdominal swelling

Abdominal swelling can be caused by many things including the following: stress, tank conditions, and constipation. Your pleco may be dying if it appears to have a bloated stomach.

This can be a sign of an internal infection due to injury or the food it’s been eating. It is important to research food options for your pleco because some brands have more harmful ingredients than good.

Checking the tank conditions and monitoring the fish’s behavior are things you can do to determine the cause of the swelling. It can also be due to stress, so separating the bloated fish from its tank mates will ensure a stress-free environment for your pleco to recover.

Feeding your fish de-shelled peas or other foods high in fiber can help decrease the swelling. Another option is giving it an Epsom salt bath, which will help remove the fluid build-up in the fish’s abdomen.

#5 Cloudy eyes

Cloudy eyes in fish appear as a white cast or film over the eye. It can be caused by elevated ammonia levels in the tank or an injury that resulted in a bacterial infection.

Unlike ich or fin rot, there are no medicinal treatments for cloudy eyes, as the problem will solve itself when the cause has been determined and fixed (water conditions, tank aggression, etc.).

The most common cause of this is poor water conditions. Checking your tank’s levels and temperatures will help you determine if the tank’s conditions are unsafe for your pleco. Isolating the fish and fixing the problem’s source is imperative to save your pleco. 

#6 Pop eye

If your fish’s eyes appear to be “bulging” out of its head, it may be suffering from pop eye or exophthalmos. It is a disease that causes fluid build-up in the eye socket, resulting in the eyes protruding out of the socket.

This can happen to one eye or both. The eyes may appear cloudy or bloody if an injury is the cause. It is usually an injury if it only occurs in one eye.

Both eyes will appear to protrude if there is an infection present. Infections are usually caused by the various bacteria and parasites that may be present in the tank.

If you discover one of your fish has popeye, check the water levels to determine if that is the cause. Infections can be treated by isolating the sick fish and consulting your vet to determine the proper treatment.

#7 Laying on its side/lethargy

High ammonia and nitrates will cause your fish to lay on its side or lack normal movement around the tank. This can be caused by not thoroughly cycling the tank before adding new fish.

Without the tank cycled, there are no good bacteria to convert the ammonia into nitrates for live plants to consume. If there are no good bacteria, harmful levels of ammonia can build up quickly as plecos produce a lot of waste.

Checking the water levels to ensure there are no harmful ammonia levels and correcting the problem with water changes will help your fish gain its movement back. 

---

How to help your pleco

The cause of most of these symptoms stems from the water conditions. In addition, there are specific treatments you can purchase to help your fish suffering from diseases like rotting fins and ich.

Temperature levels, chemical levels, and pH could be contributing factors to poor water conditions. If there are elevated levels of chemicals, perform small water changes for a couple of days to lower the concentration.

Fish can only tolerate 5% water changes every couple of hours, so make sure that you leave enough time between water changes so that your fish does not go into shock.

Although water conditions are the primary cause of these symptoms, low water temperature can also be a cause. Check the tank’s temperature to ensure it is between 72 and 78 degrees Fahrenheit.

Maracyn Two is a product that you can purchase to treat fin rot. API Liquid Super Ich Cure is another product you can purchase to treat ich.

In addition, you will want to quarantine the sick fish, as it is contagious and will spread quickly. Ensure you follow the package instructions to ensure proper dosing for your fish.

Final thoughts

Fish are fascinating creatures, and although some are easy to take care of, that doesn’t eliminate the possibility of them developing a sickness.

Most of these signs of death are preventable by monitoring the water conditions and performing weekly water changes.

Researching before owning your pleco will give you the necessary information and guidance on preventing and treating these issues when they happen because not every fish owner is perfect.