Cloudy eye on discus is a common fungus that is caused by poor water quality. You will notice that one or both of the eyes have a white cloudy film over them. Cloudy eye is often mistaken with discus pop eye. When a fish has discus cloudy eye there eyes only become cloudy but they do not seem to protrude from the head like pop-eye. The treatment for discus cloudy eye is very simple. Perform large water changes at least 50% for 3-4 consecutive days until the white film is gone. Cloudy eye can spread to other fish so make sure to keep this in mind when looking for discus fish for sale. Symptom: White film on discus eyes. cited

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.

Cause: Poor Water Quality causes weaken immune system then bacteria & fungus can set in

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.


Possible Causes for Cloudy Eye(s)

  • The most common cause of the cloudy eyes condition in discus fish seems to be poor water quality. High levels of ammonia, nitrite, and nitrate could cause the discus eye(s) to become cloudy. Too low pH or pH sock can also be another cause of the condition, especially for those newbie aquarium hobbyists who are trying to lower the pH level by adding the acid directly into water. Overall, cloudy water and any other thing that can have a negative impact on water quality may be a reason for this problem in discus. So you need to keep the fish tank water clean and clear. Nitrogen cycle and water change are the keys to have a crystal water in the tank. 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.
  • Anything that causes disorder of the immune system or immune deficiency in discus could also causes the cloudiness in fish eyes. Severe stress, diseases and conditions, bullying from other tank mates, malnutrition, weakness, impotence, chlorine, and chloramine are just some of the examples.
  • Normal medication side effects, poisoning and toxicity, overdosing medicines and etc.

The Cloudy Eye Condition/Disease in Discus Fish

Regardless of why discus has cloudy eye, it usually is not contagious to other fish. So if you have discus fish with white film on its eye(s), just don’t get scared and try to figure out the possible causes of the cloudy eye in your discus fish instead. Early diagnosis of the cause of cloudy eye in discus, can increase chances of survival and successful treatment. Cloudy eye can occur as a result of many conditions whether serious or not. Here are some of the reasons for Cloudy Eye in discus fish.

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.


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.

Is it Contagious to other fish: No

Treatment: Perform large water changes for 3-4 consecutive days until white film is gone.

[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.

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.


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.  cited