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Discus Fish Cloudy Eye Symptoms & Cure Guide

Several reasons can lead to your discus fish to develop cloudy eye disease, sometimes even both eyes can become cloudy. Poor water conditions, stress, poor diet, and even injury can lead to a cloudy eye. Below we hope to help you diagnose and treat your discus fish, view our more complete guide for other <a href='https://tropicalfish.io/article/144/discus-fish-di... title='discus fish disease treatment'>Discus Fish Diseases and Treatments.

discus fish cloudy eye disease symptoms and cure guide

Quick Guide:
What Causes Cloudy Eye?
Is Cloudy Eye Disease Contagious?
What Does Cloudy Eye Disease Look Like?
-- Slightly Cloudy
-- Very Cloudy White Eye
-- Blistered or Oozing Eye
Final Thoughts

What Causes Cloudy Eye?

It's important to note that cloudy eye disease is a symptom of something else. Meaning, your discus fish could be in poor health or have its immune defenses compromised. Many factors can lead to your discus fish experiencing poor health, such as stress, poor diet, pre-existing bacterial or parasitic infection ( depending on who you purchased your discus from ) as well as water chemistry or aquarium chemical products.

In all cases, the "cloudy" part of cloudy eye disease is bacterial and if allowed to progress it can lead to your discus fish dying. Quick treatment for the bacterial infection is important but more significant is finding out what is causing your discus fish to be susceptible to cloudy eye disease in the first place.

Poor Diet: If your discus fish is not eating or is being out-competed for food, it may not be able to sustain a healthy immune system. Assuming you're purchased your discus fish from a reputable breeder and all is well upon arrival, larger fish or even smaller more aggressive fish can out-compete and bully your discus fish, keeping it away from food. Observe your discus fish during eating times to makes sure it is getting proper nutrition. Feed high-quality protein-rich foods or live food when possible.

Poor Water Chemistry: Many discus fish keepers are crazy enough to do 100% water changes daily. The other 99% of us do water changes either weekly or semi-weekly and at least 25% to recover from evaporation and remove waste build up. Testing your water at the very least weekly will help to prevent swings in the water chemistry that can lead to your discus fish stress levels increasing and compromising its immune system. A simple water test kit can help relieve a lot of stress and confusion for you and your discus fish.

Too Many Chemicals: Discus fish don't have eyelids, so whatever is in the water is in direct contact with its eye, 24 hours a day, 7 days week, 365 days a year. It is very important to watch what you put into your tank. Marketing companies want us to buy tons of products every year that promise to lower this and raise that, reduce, increase, buffer, blah, blah, blah. Truth is, if your eyes burn when you go swimming in a chlorinated pool, imagine swimming in a mixture of the chemicals you are stirring into your tank. If it will burn or irritate your eyes, why would you make your discus fish swim in it? It's a pretty safe bet that no one is dumping pH buffers and other chemicals into the Amazon, so why do it to your tank? Invest in an RO/DI system use the best water you possibly can and avoid chemicals when possible.

Is Cloudy Eye Disease Contagious?

Absolutely NOT, now that you have your mind at ease, consider that whatever environmental, health or dietary needs to be identified quickly. Although the cloudy eye disease is not contagious, on most occasions, it is a symptom of poor water conditions, diet or injury. So you need to find out what is causing it to prevent it from happening to your other discus fish.

The easiest place to start is with your water, you can test your water quickly to make sure parameters are within range. No ammonia spikes, or other toxic swings.

What does the cloudy eye look like?

Here is a quick list to help you identify the extent, cause, and treatment for your discus fish cloudy eye disease. It is a general guide, ranging from slightly cloudy to full on oozing or bursting, it should help identify the course of treatment required.

Sightly Foggy or Opaque

A slightly foggy or opaque eye could be the beginning onset of a cloudy eye. Several factors need to be considered, especially if the discus fish has not been eating well or there has been a sudden change in water chemistry.

Start by checking your water, most of the time cloudy eye can be a sign of poor water quality. Yes, I know you change your water ten times a day and it's crystal clear. That's not what I am talking about. If you test your water parameters with a kit and you find everything is in order and within range, ask yourself if you have added any new chemicals to your water changing routine.

Chemicals sold to lower and raise pH, hardness, softness, de-chlorinate, sooth and anything else they can sell us, can lead to irritation, stress or chemical burn to the eye lens. Limiting the number of chemicals used in your daily or weekly water changing routines can help reduce the possibility of a chemical burn or irritation to the eyes. Shoot, if it will burn your eye, can you imagine swimming in it?

We also cannot rule out poor diet, as this could lead indirectly to cloudy eye disease. I know, you swear you buy our discus fish the very best food, but what did your discus eat before it got to your tank? Finding a trusted and reputable local discus fish breeder is difficult, many now import directly from overseas, from large fish farms, bringing along with them poor health and disease.


If possible quarantine your discus in a smaller ten to twenty-gallon tank, preferably the smallest tank as you will use less medication in a ten-gallon tank and it will save you a few dollars. For slightly opaque eyes, keep a bare bottom tank and treat with aquarium salt and API Furan 2 to prevent and treat bacterial infection.

Very Opaque Almost White Eye

An almost white-eye is a very progressed cloudy eye that needs to be treated right away. Taking into consideration the water chemistry and dietary points mentioned above, you need to quarantine and treat your discus fish quickly.

The white is an opportunistic bacterial infection that is taking advantage of the discus fish that is experiencing a suppressed immune defense due to stress, diet or other injuries. Cloudy eye disease is a symptom of something larger going on with your discus fish.


For an almost white eye, remove your discus fish and quarantine in a ten-gallon tank. A ten-gallon tank will help use less medication and make it easier to do large water changes if needed. Heavily oxygenate the tank and provide the cleanest water possible for your quarantine tank. Start with Aquarium Salt, about one tablespoon for ten gallons is a good start. Begin treatment of API Furan 2 as directed on the box. Monitor your discus fish closely for signs of health. Keep feeding to high-quality foods in small quantities to prevent your water from getting dirty. Check to make sure your water filter is cleaning up any excess food or siphon it out yourself to keep the tank water clean.

Blistered or Oozing Eye

Ok, you got a bad one here, but it may not be cloudy eye disease! Your discus fish could be suffering from a general eye injury caused by hitting an object in the tank, in a fight or just a good old knock up against the tank wall. Discus fish can get spooked and zip around the tank, knocking itself into anything in its way. Sometimes, as they sleep discus fish can sway into heaters, causing burns to the side of the body and even the eye.


In any case, you need to treat the blistered or oozing eye as quickly as possible! Set up a quarantine tank, preferably a ten-gallon tank, use less medicine, quicker water changes. The blistered or oozing eye is a bit more serious and can lead to discus fish death. Act quickly and pay attention to the details. Setup your tank with water filter and heavily aerate the ten-gallon tank.

Final Thoughts on Cloudy Eye Disease

Remember that cloudy eye disease is a symptom of something larger lurking within your discus health. Start with your water chemistry, if you don't have one, get a solid water testing kit. You must have a good water test kit if you are going to keep discus fish. If you are just starting out, it can be an added cost, sometimes local tropical fish stores will test your water for free. Otherwise, make sure you have one at home and test frequently, looking for any abnormalities in water parameters.

Lastly, if your discus fish is experiencing cloudy eye disease and can take a few pictures to donate to be used in this article, please upload them to our <a href='https://tropicalfish.io/forum/photography title='tropical fish photo forum'>Tropical Fish Photo Forum. Thank you!

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DiscusGuy - 4 years ago
Cloudy eye in discus fish can easily be treated if action is taken early. The main cause of cloudy water is poor water conditions. Make sure you do frequent water changes to prevent cloudy eye. If cloudy eye is not treated it can harm the fish eyes and they can go blind. There are additional details about cloudy eye here: Discus Cloudy Eye