White Spots on Swordtail Fish – How to Treat Ich? 

White spots disease (Ich or Ichthyophthirius multifiliis) is among the well-known parasitic diseases that affect tropical fish and unfortunately, it is among the most persistent diseases.

Protozoan attacks are the cause of white spots, which attach themselves to the gills, fins and the body of swordtail fish. Each white spot will look like a small grain of sugar or salt – it is usually an individual tiny parasite.

White Spots on Swordtail Fish - How to Treat Ich? 

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White Spots on Swordtail Fish – How to Treat Ich?

Ich can be damaging to your fish and might cause mobility and breathing problems – if you fail to act fast, they will cause death. After the white spot parasites have increased in your aquarium, you will have a hard time trying to control infections because they will reproduce fast.

White spots are dangerous and very contagious. After one swordtail fish gets sick, you will realize that the others are sick too after a very short time.

Signs of Ich on Swordtails

One of the signs that should tell you that your fish are affected is the appearance of the white spots on the gills and body of your swordtails. And as the disease progresses, the fish will be irritated and start scratching themselves by rubbing their body on the bottom part of the tank or the sides.

The scratching will not help at all but it might worsen the situation leading to respiratory problems, loss of appetite and eventual death of the affected fish. Some other signs that will tell you that your swordtails are affected include:

  • Production of excessive slime
  • Clamped fins
  • Fish trying to rest at the bottom of the aquarium tank
  • Abnormal swimming behaviours
  • Rapid breathing
  • Abnormal hiding of the fish
  • Some fish starts moving individually
  • Fish get tired due to the abnormal movements
  • In advanced stages, you might see redness and bloody streaks

The life of Ich parasite is of three phases – free, infecting and the biological phase. To cure the disease, you will have to treat the fish when the parasites are in the free phase.

In other words, you will have to offer the medication after the parasite latches on the body of your swordtails and starts to multiply.

After the free phase, the parasites will get into the infecting phase and they will enter into the tissues of your fish and therefore protect themselves from the medication. That means you will have a chance of trying out anti-parasitic medications and malachite green when the parasites are in the free phase.

Malachite green (a dye) is among the effective medications that attack the white spots, but unfortunately, only a few fish will bear the treatment. So, before you use it, you will confirm with your vet that it is safe for your fish.

How to Treat White Spots on Swordtails?

After the disease affects your swordtails, they will experience movement and breathing problems. Fortunately, there is a cure for the disease. To control it, you will have to treat the affected fish and improve the tank condition. Here is what to do.

Do water changes

Replacing the water in your aquarium tank with a new one will help cure the disease while in the early stages but for this method to be effective, you will have to increase the temperature too. It will speed up the biological phase and reduce the exposure time, therefore, helping the medicine work more effectively.

If one or most of your swordtails are affected, you will have to start the treatment immediately. Do 23-30 percent water changes each day to fight the disease. The water change will reduce the nitrate build-up, eliminate the waste material, debris and ensure that the swordtails are getting enough oxygen.

Use a water testing kit to know whether the water in your aquarium tank is in good condition.

Raise the temperature

Water temperature plays a vital role in the health of your fish.  A sudden water change will affect the immune system of the fish and cause other environmental diseases and parasitic infections.

Generally, tropical fish will require water temperatures ranging between 75-80 degrees Fahrenheit (25-27 degrees Celsius).  Any water fluctuation exceeding +/- 30 degrees Fahrenheit from the normal range will make your fish more susceptible to diseases.

For water changes in your tank, you will have to buy a good thermometer and heater. Check the temperature more often to prevent huge changes.   Generally, ich results from stress and some other factors that reduce the immunity of fish. You can lessen the infection or remove it by raising the water temperature.

Use aquarium salt

Apart from the higher temperature and daily water changes, you can use salt to treat the ich. All you need to do is add some salt in the aquarium tank or treat individual fish with salt baths to kill all the infectious external parasites.

Salt treatment is more effective because it prevents the secretion of fluid by ich and increases the natural secretion of mucous in addition to making a slim coat to keep the ich away. Take pure NaCl and add 1 tablespoon to 5 gallons of water or around 3-5 grams per every litre of water.

Use it to treat the fish at least once every two weeks. The other option is aquarium salt, which you can get in the local pet stores.

Dissolve the salt in warm water before adding it to the tank so that it can help improve the temperature. After you have made a solution, add a half dose to the tank and wait for around 12 hours before adding the second half.

The dosage is helpful for the highly sensitive fish. If the swordtails become lethargic or start breathing rapidly, you will have to change some of the water to remove the excess salt. Swordtails respond well to salt treatment. And before using the salt, you will have to remove the activated carbon from the water filter.

Never use table salt because it contains iodine, and never use salt along with medication because they are known to lower the oxygen level. Do at least 25 percent water changes after every few days and add enough salt again. After you have done that, change the water partially from the tank and do not add any more salt.

Use medication

If water changes, temperature increase and use of salt fail, medications might help. Medications such as formalin, methylene blue, malachite green, copper sulphate and potassium permanganate are known to treat ich in swordtails more effectively.

Before using any medication, read the label carefully to identify all the special instructions and the dosage information. In addition to that, you will have to gather warnings about the aquarium plants, your health, the fish and other organisms (such as snails and shrimps) in your aquarium tank.

Before administering the medication, change the water and remove the gravel from the aquarium. Remember to remove the carbon from the filtration system because it can reduce the active chemicals in the medicated water.

Typically, most medications are ineffective due to unwarranted dissolved organics like nitrates in your tank. When that is the case, do not change the water during treatment. Quality medication will eliminate ich from your swordtails within a short time. Do not forget to raise the water temperature when administering it.

How to Prevent Ich in Your Aquarium?

White spot disease is among the deadly and widespread disease. At least every swordtail fish will get affected at least once in its lifetime. To be certain that your fish are safe, you have to take good care of them and prevent the disease. Here are some of the things you should do to keep your swordtails safe.

  • Each time you change the water, ensure that the temperature and the PH level of the old and new water are the same.
  • Add decorations and plants into the aquarium tank. For better results, you will have to boil the objects before you introduce them into the tank. You can also disinfect them.
  • Before adding new fish to your aquarium, keep the new fish in a separate tank for at least two weeks. That way, you will avoid introducing parasites in your aquarium accidentally.
  • Try to get the fish straight from the supplier. That will allow the fish to avoid the hassles associated with passing through a wholesale store, a retail store and finally to your home. In other words, you will help the fish avoid shipping stress.
  • Never overcrowd the swordtail fish in one aquarium tank. Keep the right number of fish depending on their size and the size of your tank. The excess number of fish in one community tank will lead to stress, diseases and high mortality rates.
  • Work hard to maintain high-quality water in your aquarium tank. Remember to check the PH, temperature and hardness at least once every week.
  • Never use the pet store water in your aquarium

Ensure that the water quality is high and offer the fish a balanced diet so that they can remain disease-free and live longer. Quarantine every new swordtail for more than two weeks before you add it into the community tank.


Ich cannot affect humans but it can easily kill all the fish in your aquarium tank. Currently, it is the most widespread fish disease but that should not mean it has to affect your swordtails. With a good understanding of the disease and proper care, you will manage to keep all your fish safe.

Follow the preventive measures and if your fish are already affected change the water, raise the temperature and use the right medication. Act immediately to avoid losing them.

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