How to Cure Fungus on Aquarium Fish

If your fish has a white- or gray-colored growth on its mouth or body (often with a fluffy texture like cotton), it could have a fungal infection. Fungal outbreaks are often caused by stressful or poor water quality conditions and can rapidly lead to secondary diseases, so it’s important to address the problem immediately. This article will discuss both how to treat fungus and how to prevent it from returning.

When you see any symptoms of illness, the first thing we always recommend is a thorough cleaning of the aquarium. Before we begin treatment, we want to ensure that the environment of the fish is healthy and free from stress. You can see the condition of your fish by cleaning the glass. Then, you can use a siphon and vacuum the substrate to change the water. For a step by step guide on cleaning an aquarium, see this article.

Fungus can often be prevented. The next step is to determine the source of the infection. The source of the problem must be addressed before treatment can begin. If the source is not identified, then the fungus might return.

What Causes Fungus In Fish?

Bad water conditions are common causes of fungal infections. This is why we see so many betta fish suffering from this disease. They are often kept in small containers that have no heaters or filters. Bettas thrive at temperatures of 78-80 degrees Fahrenheit, so they will need a heater to keep them warm in rooms that are below this temperature. To prevent their waste from rapidly fouling the water, you should keep them in an aquarium with at least 5 gallons. Doing regular partial water changes and adding live plants (especially floating plants) to a fish tank helps to remove toxic waste compounds before they affect your betta’s health.

Nutrient deficiencies can be another reason why fish get fungus. Fish need to eat a varied diet in order to stay healthy. Feeding fish from the same jar of flakes all the time is like feeding a person only hamburgers every day. Although they may be able to survive, their bodies are likely not in the best of health. You should ensure that your pets have access to a variety of food so they can get all the nutrients they need and that you provide them with high-quality, fresh foods. Although the expiration date may indicate that the food will be good for three more years, air and moisture can get into the containers, which can cause the food to go bad in just a few months. You can freeze the food if you don’t have enough fish for the entire jar. This will preserve the freshness of the food until you are ready to use it. Don’t use wet fingers to remove food from the container. This could cause food to turn moldy and can lead to other diseases.

To ensure that your fish get the essential nutrients they need to improve their immune system, eat a wide variety of high-quality food.

Many livebearers, including fancy guppies or mollies, get fungal infections very quickly after being brought home from the pet shop. The reason aquarium fish are less resilient than livebearers is explained in a separate article. These fish are often mass-bred in countries that don’t have enough fresh water. Therefore, it’s cheaper to raise them in a mix of fresh water and salt water. Your guppies who have been raised in brackish waters for most of their lives, and then suddenly move to a pure freshwater environment, are often in a weak state. This makes them more susceptible to foreign pathogens such as fungus spores.

End result: eliminate as many stressors as possible. Minimize bullying and food aggression among African cichlids. Keep the gravel clean for bottom dwellers and the water quality for sensitive species high. Avoid keeping shy fish around loud TVs, bright lights that create moving shadows, or high traffic areas in your home. Consider moving older animals that have weaker immune systems into a “retirement tank” with less activity and competition.

How Do You Get Rid of Fungus on Fish?

Maracyn is recommended for fish with mouths that show signs of fungus and rot. Columnaris is a type of bacterial infection that looks like a cottony growth or grayish-white areas around the mouth. This should be treated with antibiotics. Clean the aquarium thoroughly and get rid of any chemical filtration such as activated carbon or Purigen. Follow the manufacturer’s instructions and use 1 packet per 10 Gallons of water. Repeat this process every 24 hours for five consecutive days. The infection may still be present even if symptoms disappear.

Maracyn or Ich-X can be combined if the fungus is found elsewhere on the fish’s skin. Ich-X contains formaldehyde, methanol, and malachite green chloride, which are effective against fungal infections. Before treatment, clean the aquarium and remove any chemical filtration. If you have a mild fungal infection, use one packet of Maracyn along with 1 teaspoon Ich-X to treat 10 gallons. Let the medication sit for one week to ensure that all symptoms disappear. If the symptoms still remain or if the fungal infection is severe to begin with, use 1 packet of Maracyn and 1 tsp of Ich-X per 10 gallons of water, and repeat the dose every 24 hours for 5 days in a row.

Salt is a great treatment for both body and mouth fungus. While any regular salt made from sodium chloride (NaCl) can be used, this article will use aquarium salt or rock salt. We are not talking about marine salt or Epsom salt.

We have discovered that salt is tolerated by most fish species, including tetras and barbs as well as African cichlids. However, other fish like anchor catfish are very sensitive to it and should never be exposed to salt. Start with a low salt solution of 1 tablespoon salt per 3 Gallons of water to ensure your fish is able to endure salt treatment. If the fish is healed after one week, gradually remove the salt via a series of weekly 30% water changes. You will need to increase salt concentration if the fungus remains active. You can read our complete article on salt dosing for detailed instructions. You can also use salt in conjunction with Ich-X to pack a powerful one-two punch against the fungus.

What about other fungal medicines?

In our experience, herbal remedies are not very effective against fungal infections. Fish that are afflicted by the disease will need stronger medications to protect their lives. After years of working in a fish shop and helping hundreds of customers, we discovered that Maracyn, IchX, and Salt are the best treatments against fish fungus.

Ultimately, fungal spores are always present in our aquariums, but full-blown infections are usually preventable. You can boost your fish’s health by providing them with the proper nutrients and stress-free environment.

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