Ich in Fish

Ich is also known as "ichthys" or "white spot disease". It is a parasitic infection that commonly affects fish. Especially those kept in aquariums.

Ich is a very common and contagious disease in freshwater aquariums and can spread quickly between fish. The parasites attach themselves to the fish and feed on their skin and bodily fluid, causing irritation, inflammation, and potentially lethal infections.

Symptoms of Ich in fish

Symptoms of Ich include white spots on the fish's body, flashing( rubbing against objects, lethargy, loss of appetite, and rapid breathing.

  • White spots on the skin and fins of the fish. This spot may be small and barely visible or large and distinct, depending on the severity of the infection.
  • The fish may become restless and swim erratically, often rubbing against the aquarium walls, decorations, or substrate.
  • The fish may lose its appetite and become lethargic, spending more time at the bottom of the tank or hiding.
  • The fish may develop fin rot or other secondary infections, as the parasites weaken their immune system.
  • In severe cases, the fish may experience rapid breathing or gasping for air, which can lead to death.


  • Treatment includes medications such as copper sulfate, formalin, or malachite green, as well as raising the temperature of the aquarium water.
  • Prevention is always the best option, so it's important to maintain good water quality and quarantine a few fish before adding them to an established aquarium.
  • Salt treatment adding salt to the aquarium can help to reduce the severity of Ich. A concentration of 1-3 tablespoons of aquarium salt per gallon of water can be added. It is important to note that not all fish are tolerant to salt, so research should be done before attempting this treatment.
  • Increased water temperature, raising the temperature of the aquarium to 82-86° F can help to speed up the life cycle of the parasite, making it more susceptible to medications and salt treatments.
  • UV sterilization, installing a UV sterilizer in the aquarium can help to prevent the spread of ich by killing free-swimming parasites.
  • It is important to remember that Ich can be a very persistent and hardy parasite, so treatment may need to be repeated several times before it is fully eradicated. Maintaining good water quality and a healthy environment for your fish can help to prevent Ich and other diseases from occurring in the first place.

Can Ich be Prevented?

Yes, there are several steps you can take to prevent Ich in your fish tank, including maintaining good water quality, avoiding overcrowding, quarantining new fish before adding them to the tank, and regular cleaning.

How do fish get infected with Ich?

Fish can become infected with Ich in several ways, including poor water quality, stress, or contact with other infected fish.

Fish can become infected with Ich through various means, including-

  • The Ich parasite is commonly found in the water of infected tanks or ponds. Fish can become infected by coming into contact with the parasite in the water.
  • Fish can also become infected with Ich when new fish are added to a tank or pond and are already infected with the parasite.
  • Stress fish that are stressed, such as those that have been recently transported or those that are kept in poor water conditions, are more susceptible to Ich infections. Stress weakens a fish's immune system, making it more vulnerable to parasites like Ich.