How to Treat Tropical Fish with White Spot Disease

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How to Treat Tropical Fish with White Spot Disease
How to Treat Tropical Fish with White Spot Disease

White spot disease, also known as ich, is a parasite that most tropical fish fans will have to deal with at some point. The disease is responsible for more fish deaths than any other. It is more common in aquarium fish because of the close contact with other fish and the stress involved in living in such an environment, as opposed to open water. Ich can be found in tropical freshwater and saltwater fish, and the treatment is different for each ecosystem and its inhabitants.


Part 1 of 5: Understanding how ichthy works

Treat Tropical Fish With White Spot Disease (ich) Step 1

Step 1. Know how to distinguish the disease in freshwater and saltwater fish

This disease works the same in both types of fish, but it has different life cycles and cures. In both types of water, the parasitic protozoan attaches to the fish to continue its life cycle. In nature, ich is less of a problem, as few parasites can find a host. When they find it, they end up falling off the fish, which can swim away and recover. However, in a closed tank, parasites can easily attach themselves to fish, multiplying and infesting, eventually leading to the death of an entire tank.

  • In fresh water, ich is known as "ichthyophytyriasis".
  • In salt water, it is known as Cryptocaryon irritans, and is often confused with other parasites that produce white spots. Marine ich may take longer than freshwater to replicate, but it only has 12 to 18 hours to find a host before it dies. Freshwater fish can withstand up to 48 hours without a host.
Treat Tropical Fish With White Spot Disease (ich) Step 2

Step 2. Understand that stress is a factor that affects a fish's chance of being infected

As ich is quite common, most fish have developed a good immunity to it. However, stress can suppress the immune system, and this is where ich is most prevalent. Stress can be caused by:

  • Incorrect temperature or poor water quality;
  • Other aquarium residents;
  • New residents in the aquarium;
  • Incorrect diet;
  • The handling and transport of fish;
  • Your home, especially if it's prone to loud sounds, doors that shake or slam, or a lot of traffic near the aquarium.
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Step 3. Learn to identify the symptoms of ichthyus

Symptoms can be seen in your fish's appearance and the way it acts. The most obvious is the appearance of white spots that resemble grains of salt and that give the disease its name. Common symptoms of the disease are:

  • White spots on the fish's body and gills: the spots can even come together and form white areas. Sometimes the ich only focuses on the gills.
  • Excessive Itching: Fish may rub heavily against plants or aquarium rocks in an attempt to get rid of parasites or because the disease is causing irritation.
  • Fins retracted: The fish is all the time with the fins folded against the body instead of letting them open and rest freely beside the body.
  • Difficulty breathing: If the fish is looking for air at the surface of the water or swimming near the aquarium filter, it is probably feeling short of air. The ich in his gills makes it difficult to absorb oxygen from the water.
  • Loss of appetite: If the fish is not eating or is spitting out food, this can be a symptom of stress and illness.
  • Recluse Behavior: Animals often hide when they are sick, and any change in normal behavior is often a symptom of stress or illness. The fish can hide in the decor or become less active than usual.
Treat Tropical Fish With White Spot Disease (ich) Step 4

Step 4. Treat the fish when the parasite is most vulnerable

Ich can only be killed when it is not attached to the fish, that is, when the mature parasite falls from the animal's skin to replicate. Whenever it is attached to fish, it is protected from chemicals, and treatment is ineffective. The ich's life cycle has several stages:

  • Trophon stage:

    is when the parasite is visible in the fish. It burrows under the animal's mucus covering, forming a cyst that protects it from the chemicals, so treatments don't work. In a typical aquarium with a temperature of 24 to 27 °C, the trophon or feeding stage lasts a few days until the developed cyst falls off the fish.

  • Tomonte or tomito stage:

    at this stage, treatment is possible. The parasite, or tomonte, will float for several hours in the water until it attaches itself to a plant or other surface. Once trapped, it will begin to rapidly divide or replicate within the cyst. In a few days, the cyst will open and new organisms will start swimming in search of a new host. The freshwater mound can replicate in just eight hours, while the saltwater mound can take three to 28 days to replicate.

  • Teronte stage:

    freshwater terontes must find a host or fish within 48 hours, or they will die. The salt water ones only have 12 to 18 hours. Therefore, one way to ensure that an aquarium is ich free is to leave it without fish for a week or two.

Treat Tropical Fish With White Spot Disease (ich) Step 5

Step 5. Observe the temperature of the aquarium

Higher temperatures accelerate the parasite's life cycle. In a warmer aquarium, the cycle will take about two days to complete. In cooler aquariums, the same cycle can take weeks.

  • Never increase the temperature of your aquarium too much. This attitude can stress fish, and some do not tolerate higher temperatures.
  • Most tropical fish can withstand temperatures of up to 30 °C. Always consult a tropical fish expert or learn about your fish to find out what temperatures they can withstand.

Part 2 of 5: Easy Ichmic Treatments

Treat Tropical Fish With White Spot Disease (ich) Step 6

Step 1. Raise the water temperature to 30°C

Slowly increase the temperature by 1 °C per hour until you reach the correct value and maintain this temperature for at least 10 days. High temperatures speed up the ich's life cycle and can also prevent tomonts from reproducing.

  • First, see if the fish can handle these higher temperatures.
  • If they can withstand temperatures of more than 30 °C, raise to 32 °C for three to four days and then lower back to 30 °C for another ten days.
  • See if your tank is getting enough oxygen or aeration, as water holds less oxygen when it's warmer.
  • At the same time, you can treat the water with salt or medicine every day.
  • See if your fish can handle the temperature rise. Watch their reaction to a gradual warming of the tank or read to see how much they can tolerate.
Treat Tropical Fish With White Spot Disease (ich) Step 7

Step 2. Increase aquarium oxygen or aeration to improve the immune system and quality of life of the fish

Since ich inhibits the fish's ability to breathe and absorb oxygen, increasing aeration can help improve the animal's immune system and prevent it from suffocating to death. There are several ways to increase tank oxygenation:

  • Lower the water level so that when filtered water reaches the surface, it creates more oxygen.
  • Put more oxygenators in the aquarium or move them closer to the surface of the water.
  • Use the round aerators to make bigger bubble streams.
  • Use the pumps not only to increase oxygenation, but also to improve water movement in the aquarium.

Part 3 of 5: Intermediate treatments

Treat Tropical Fish With White Spot Disease (ich) Step 8

Step 1. In freshwater tanks, treat the ich with aquarium salts

Dissolve 1 teaspoon of salt for every 4 l of water in a little of the separate aquarium water and add the mixture to the tank. Leave the salt in the freshwater aquarium for 10 days. Salt disrupts ichthy fluid regulation and also helps to develop your fish's natural mucous coverage, protecting them from parasites. Combine the salt to heat to kill the ich even more effectively.

  • Use aquarium salts made especially for fish, not table salt, which has iodine.
  • Never use medication together with salt and heat, as salt and medication can react and deplete the oxygen in the tank.
  • Change 25% of the aquarium water every few days and add just the right amount of salt to the water that was removed. At the end of the treatment, make partial water changes, but do not add more salt.
Treat Tropical Fish With White Spot Disease (ich) Step 9

Step 2. Make partial and daily 25% water changes

Changing some of the water every day can help remove some trophons and thyme from the aquarium, and also add oxygen to the water. Use treated water so that the extra chlorine doesn't stress your fish or mess with their wounds.

If water changes stress your fish, decrease the amount of water changed or the frequency of changes

Part 4 of 5: Advanced treatments

Treat Tropical Fish With White Spot Disease (ich) Step 10

Step 1. Use medicinal products to treat the aquarium

There are many products available at your local pet store that can help treat ich. Always follow the directions on the drug label to know the correct doses and whether the product can be used on your type of fish, especially if you have invertebrates such as snails, shrimp and clams.

  • Always do a water change and vacuum the gravel before administering the medicine. This is most effective in a clean tank, with no other organics or dissolved nitrates to interfere.
  • Remove carbon from the filter as it can neutralize or trap medications added to the tank.
Treat Tropical Fish With White Spot Disease (ich) Step 11

Step 2. Use copper to treat saltwater fish with ich

Since saltwater ich lasts much longer in the thymite stage, copper is often added to the tank for 14 to 25 days and works the same way as salt to destroy ich. Using copper, however, requires you to put in the exact and correct dosage and check levels carefully daily using a copper ion test kit.

  • Always follow the product instructions.
  • Remove carbon from the filter as it can neutralize or trap medications added to the tank.
  • Copper combines with calcium carbonate or magnesium carbonate based stones, sand and gravel, so only use it in empty tanks.
  • This mineral is very toxic to invertebrates, corals and plants. Separate these elements and treat them with other safe methods.
Treat Tropical Fish With White Spot Disease (ich) Step 12

Step 3. Use stronger chemicals to treat saltwater ich

These methods can be dangerous alternatives. Some even harm the fish, and need to be constantly monitored so that the levels don't reach a point capable of killing the animals. Always read the packaging of these medications and wear protections such as safety glasses and gloves when handling them. Some of them are:

  • malachite green:

    similar to chemotherapy in humans, it impairs the abilities of all cells to produce energy, which is vital for metabolic processes. This chemical does not differentiate a fish cell from that of an ich parasite.

  • Metal:

    Methanal kills microorganisms by reacting with the cell's proteins and nucleic acids, which alters the cell's function and structure and is often used to preserve biological species. It can damage the filter system, lower oxygen levels and kill invertebrates or weaker fish.

Part 5 of 5: Preventing Ich

Treat Tropical Fish With White Spot Disease (ich) Step 13

Step 1. Never buy fish from an aquarium in which any other animal has symptoms of white spot disease

Before purchasing aquarium inhabitants, it is always best to observe each fish in the store to see if there are symptoms of disease. Even though the desired fish doesn't seem to exhibit symptoms of ichthyus, it has still been exposed and can carry the parasite into your home aquarium.

Some fish have very good immune systems and may only act as disease transmitters. By introducing one of these transmitters, you will be exposing your current fish to the parasite, and their immune system may or may not be as strong as the new fish

Treat Tropical Fish With White Spot Disease (ich) Step 14

Step 2. Quarantine new fish for 14 to 21 days

Set up a separate, smaller tank so you can watch the new fish and see if they have symptoms of the disease. If there is any disease present, treatment will be much easier, but always use full doses of medicine. Don't think that a smaller tank means using less product.

When adding new fish to a quarantine tank or any tank, never add the water it was in to your main tank. This way, you decrease the chances of transferring tomatoes to your tank

Treat Tropical Fish With White Spot Disease (ich) Step 15

Step 3. Use separate nets for separate aquariums

This measure prevents the introduction of diseases to other aquariums. Likewise, use different sponges and other cleaning tools for each tank.

If you can't buy multiple nets, sponges, and cleaning tools, let each item dry completely before using it in another tank. Ich does not survive in dry environments

Treat Tropical Fish With White Spot Disease (ich) Step 16

Step 4. Buy plants only from aquariums without fish

Plants in fish tanks carry more disease than those grown and sold separately. Alternatively, you can quarantine them for ten days in a fish-free aquarium and treat them with ichthyic medications to make sure they are not infected.


  • Change or discard sand, gravel, rocks, and other aquarium decorations when treating the ich. It tends to stick to surfaces in order to replicate. Wash and dry these items to kill the parasite.
  • After finishing the treatment with salts or medication and eliminating all symptoms of ichthyus, change the water slowly until you are sure that the medicine has come out. Prolonged exposure to chemicals can be stressful and harmful to fish.
  • If you really want to take care of your fish, buy a microscope and collect a mucus sample to identify white spot disease. There are other parasites that can cause itchiness, fin retraction, and other symptoms, and they may not be affected by ictium treatments. For best results, identify the parasite prior to treatment.

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