Why Does My Discus Fish Have Cloudy Eyes? – 11 Treatment Steps


Cloudy eyes are a Discus fish disease caused by a bacterial infection and cause the appearance of white film in the eye of the Discus fish. Cloudy eyes can be a symptom of a disease or different diseases in a Discus fish, and it can occur in either one eye of your Discus or both of them. You have to observe your fish regularly and carefully to detect this symptom.

NOTE: Cloudy eyes disease can be very dangerous for your Discus fish if not detected early because it may likely be a symptom of a more severe and sensitive disease or infection.

Table of Contents

Firstly, let’s look at the symptoms of cloudy eye disease.

Discus Cloudy Eyes Symptoms

  • Slightly foggy eye.
  • Blistered eye.
  • Almost white-eye.
  • Loss of Appetite.
  • Bursting out of the eye.

Discus Cloudy Eyes Disease Details

The cloudy eye is a common Discus fish disease condition not only among Discus but in most other tropical aquarium fish. This disease is mostly not a disease itself. Rather, it can be a symptom that may be a result of diseases in the body of the fish.

Mortality caused by cloudy eye disease is very rare and can only happen if the fish is not treated early and reaches the late stage of the disease. It is paramount to diagnose the cause of a cloudy eye in Discus early. This can increase the chances of survival and successful treatment in your Discus fish.

A cloudy eye can occur as a result of many other diseases or conditions in your Discus fish, both the severe and non-severe ones.

Are Cloudy Eyes In Fish Contagious?

Certainly not, cloudy eye disease is not contagious, so if you observe the above symptoms in any of your fish or fishes do well to discover the cause of it immediately. As early treatment will always do you good. It is also safer and better to isolate sick fish, it makes the drugs more effective.

NOTE: Isolating effected Discus, channels the treatment to that particular fish and prevents wastage of the medicine in the large tank.

Why Does My Fish Have Cloudy Eyes?

This Discus fish disease is mostly caused by poor water quality. As an aquarist, healthy water parameters should be the routine in your aquarium because this can cause cloudy eye disease and may have an adverse effect on the immune system of your fish.

Any act that weakens your Discus fish’s immune system should be avoided as soon as possible, including severe and constant stress, bullying from other tank mates, malnutrition, weakness, and so on. It can eventually cause cloudiness in your fish eyes.

NOTE: The best cure is to find possible underlying causes of the condition. Regular water change is one of the main keys and adding of aquarium salt. This may only be helpful in the early stages of this disease.

Discus Cloudy Eyes Causes

The following are the possible causes of Discus cloudy eye disease.

  • Poor water quality.
  • High levels of ammonia.
  • Unstable Nitrite levels in the water.
  • Drug interactions.
  • High levels of chlorine or chloramine.
  • Fluctuation in water temperature.
  • High Discus salt dosage.
  • Medications.
  • pH shock.
  • Water conditioners.
  • High TDS levels.
  • Stress.
  • Dietary deficiency – Lack of vitamin A.

The above are causes of cloudy eyes in your Discus, which may be accompanied by or result in other diseases and infections in the Discus fish.

NOTE: These causes can compromise the immune defenses of your Discus and lead to poor health of the fish.

Cloudy eyes disease, also known as foggy eyes, may be a symptom of a disease like Popeye disease another Discus eye disease where the eye of the Discus shoots out, it can also affect one eye or both.

How Do You Treat Foggy Discus Eyes?

Discus Cloudy Eyes (Foggy Eyes) 11 Treatment Steps:

[STEP1] – Quarantine Your Sick Discus

Quarantine your sick Discus fish/fishes in a smaller tank, preferably a ten or twenty-gallon tank as you will use fewer medications there and it will save you some money and make heavy water changes easier if need be, the smaller, the better except the sick fishes are much then you can isolate in a bigger quarantine tank.

[STEP2] – Heavily Oxygenate The Tank


Oxygenate your tank and use the best water you can get, oxygen is an important factor in healing sick Discus, so better to use an air stones bubbler in your tank.

[STEP3] – Remove The Filter’s Carbon

This is a very important step before applying the medications in the below steps, cause carbon will observe the medication quickly which will result in useless medication in the tank.

NOTE: It is recommended that active carbon, UV filtration, and protein skimmers are turned off during treatment.

[STEP3] – Treat With Aquarium Salt

Keep a bare bottom tank and treat with aquarium salt and API furan two on prescription to treat the bacterial infection.

NOTE: For Discus salt dosage, one tablespoon for a 10-gallon tank will do.

[STEP4] – Treat With Antibiotics

Treat your aquarium (hospital quarantine aquarium) with antibiotics such as Melafix for cloudy eyes.

NOTE: Melafix dosage is (10ml for every 380 liters) treat every day for 7 days.
HINT: Melafix is taken from the Tea Tree (Melaleuca), Melafix is very effective in the treatment of Discus cloudy eye disease.

[STEP5] – Clean Up Excess Foods

Clean up excess foods from your main quarantine tank or observe if your water filter has done that already.

[STEP6] – Feed High-Quality Foods

Feed high-quality foods in small amounts; Discus may not eat much, especially foods rich in vitamins.

[STEP7] – Observe Frequent Water Changes

Observe frequent water changes for the hospital tank, do a regular water change for the main tank to clean it, and avoid using excess medicine.

[STEP8] – Check For Secondary Infections Symptoms

Check for symptoms of other secondary infections.

[STEP9] – Observe Your Discus

Observe Your Discus closely to know if she is recovering or not.

[STEP10] – Change Out The Filter Carbon

Change Out the main tank carbon in the Filter.

[STEP11] – Do Not Return Your Fish To The Main Tank Until It Is Completely Recovered

Cloudy Eyes Future Prevention Tips

Preventive measures are always better, risk-free, and cheaper than treatment. The following can help you avoid cloudy eyes as much as possible.

  1. Keep the Discus fish environment clean.
  2. Observe 25% water changes once a week – You may observe water changes of 25% – 30% weekly but to avoid poor water chemistry test your aquarium water regularly.
  3. Clean carbon in a filter in the space of two to three weeks.
  4. Feed your fishes with food rich in vitamins – You should feed your Discus well. If you observe your Discus not eating or being bullied by stronger fishes, it may shut down its immune responses and cause cloudy eye disease. Feed with high-quality protein-rich foods or live foods when necessary.
  5. Maintain a steady pH of 6.4 – 6.8 – Get a test kit to be able to test your water at least once a week; this will help you avoid fluctuations in water chemistry, prevent an increase in the stress levels of your fish, and will also decrease the chances of the immune system of the fish getting compromised.
  6. Avoid chemical treatment – Due to the fact that Discus fishes don’t have eyelids, everything in the water is in direct contact with its eyes always and at all times. So, you have to be very careful with the medications and chemicals you add to your aquarium water. Their medications should be prescribed and in the correct dosage.

You don’t have to use some of the chemicals some marketers convince you to buy, a mixture of these chemicals can cause your eyes to burn when you go swimming so it can also cause great harm for your Discus.

Avoid chemicals as much as possible and investing more in an RO/DI system makes your aquarium water at its best at all times.

NOTE: Some of these chemicals can cause cataracts, which has no cure for your fish. Cases of fish lost an eye can also occur.

How Do I Fix Cloudy Eyes In My Discus?

Cloudy eyes can easily heal when discovered early, and treatment commences immediately. In the early stage of this disease, you can perform the first treatment of changing out carbon from the filter, followed by 25% water changes for four days if it persists, treat with the aquarium salt for 7 days and observe, 1 tablespoon for every 10 gallons of water.

NOTE: If it persists after this time, then carefully follow the treatment steps listed above.


Discus fishes are more prone to cloudy eye disease than other fish species because they are naturally very sensitive. Cloudy eye disease is caused by bacteria build-up in the aquarium. Eye fungus is an environmental condition that should be attended to early because if it is not attended to soon enough, it can destroy the pupil of the fish and bring about cases where the fish lost an eye or both eyes. This disease can occur overnight and may take time to heal, sometimes in a week or two weeks.

Generally, fishes are sensitive, and things as simple as water changes, temperature changes, pH changes, etc. can cause stress a huge amount of stress, so the question should not be How do I Fix cloudy eye fish but what are the preventive measures to this disease. It is cheaper and safer for you and your fish, respectively.


This is me Firas Sameer, the founder of DiscusRescue.com, I am an aquarist guy with a passion and love for Discus fishes, I am learning every day with my hobby at home and sharing the things I am learning from my experience with you.

4 thoughts on “Why Does My Discus Fish Have Cloudy Eyes? – 11 Treatment Steps

  1. Recent days, my tank sudden rich in ammonia, causing discus to sick. Very bz with water change daily for the past 2weeks.
    I realised there are 2 fishes with eye cloudy and others with fin torn.

    1. One of the reasons why ammonia is raising is the too much water changes, if you do a lot of water changes you will not give them time for the beneficial bacteria to build up, another thing is you need to provide good aeration to your water, add like air stones with a good air pump to fill the water with good oxygen.

      there are many factors why you have a poor water quality which should lead Discus fish to diseases like cloudy eyes.

      Better to check my other article on the best Discus fish practices to have healthy Discus in your hobby.

      5 Main Tips On How To Keep Healthy Discus – Practical Guide

  2. I just got a discus in my tank. Next day is eye is half way cloudy. I changed some of the water and went to the pet store. They gave me a fungi treatment drops and salt to put in the water. Today it is fully clouded over. I have a feeling it’s just going to get worse. I also have an angelfish in there. Idk anything about tanks and water and need help on what to do

  3. I am treating a Discus with cloudy eye. He was rearing 40 young but I removed them when I noticed that the fry were leaving pits in the skin of the parents. Father also had a cloudy eye, so I’m treating now with Melafix. I noticed in the above text, that there’s two references to adding salt in the water. Above it says 1T for 10G but in the Related Questions it recommends 1 tea for 10G (1/3rd the treatment). Can you clarify?

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