from the blog

Aquarium Fish Diseases: The Four Basic Types

Caring for fish

September 26, 2020

Even if you make sure to perform regular water changes and keep your aquarium filter running properly, it is likely that your fish will contract a disease at some point. Keeping your tank clean and feeding your fish a healthy diet are two of the most effective ways to prevent disease, but you cannot completely protect your fish. Aquarium fish diseases fall into four different categories and if you understand the basics about these diseases you will be better equipped to deal with them. Knowledge is the key to quickly diagnosing and treating aquarium fish diseases and the more quickly you are able to do so, the greater the chances are that your fish will recover.

Bacterial Diseases

Goldfish with Popeye

Poor water quality is the most common cause of bacterial infections and fish that are already stressed due to poor tank conditions or prior injury have an increased susceptibility to bacterial diseases. Bacterial infections may be either external or internal but external infections are the most common. External bacterial infections often produce symptoms like ragged or rotting fins, lethargy, reddening of the skin and ulcers. Internal infections may result in hemorrhaging and fluid build-up. Some of the most common bacterial infections include fin rot, dropsy, tuberculosis and red pest. Salt baths are a common treatment for bacterial infections, though medications such as potassium permanganate and chloramine-T are also effective.

Fungal Diseases

Fungal diseases are some of the most common among freshwater fish and examples of fungal diseases include cotton mouth, egg fungus and gill rot. Because fungal spores are already present in most aquariums, it only takes a decline in water quality for the disease to spread. Fish that are already stressed or injured are much more likely to contract fungal infections. Common symptoms of fungal diseases include white cottony growths, excessive mucus production and difficulty breathing or eating. Fungal infections are most often treated with antifungal agents such as phenoxyethanol and Malachite Green, though salt baths are also known to be effective.

Parasite Diseases

Parasite infections are caused by microscopic organisms which enter the bodies of fish and feed off of them, often killing the fish in the process. Common parasite infections include Ich, Hexamita, Chilodonella and Velvet. These diseases often produce symptoms such as ulcers, visible cysts or spots, loss of appetite and rubbing against tank objects. Increasing tank temperature can sometimes help to speed up the life cycle of the parasite but more common treatments include potassium permanganate, formalin and acriflavine.

Viral Diseases

Viral infections are some of the most difficult to diagnose and to treat because they are largely internal and cannot be treated directly. The most recognizable symptom of viral disease is wart-like growths, though red streaks or bruises on the skin and fins are also common. Some viral diseases may result in bloating, hemorrhaging, anorexia and lethargy. Fish pox, Lymphocystis and viral hemorrhagic septicemia are some of the most common viral infections. Most viral infections have no cure and even if the infected fish survives it may be a lifelong carrier of the disease.

Tips for Keeping Fish Healthy

You already know that keeping your fish tank clean is the key to keeping your fish healthy. What you may not realize, however, is that something as simple as adding an EcoBio-Stone to your tank can make a big difference in maintaining high water quality. EcoBio-Stones are made from porous volcanic cement and infused with beneficial bacteria. When the stone is immersed in water, the beneficial bacteria multiply to form a colony in your tank that will help maintain the nitrogen cycle and clarify the water. When combined with routine water changes and adequate filtration, an EcoBio-Stone can help to keep your aquarium clean and clear which will lower the chances of your fish contracting a disease.