How To Cure Guppy Ich? (Signs+Causes Of Ich).

Ich or white spot disease is the most common disease among fishes, and every aquarist wants to know how they can prevent their fish from ich and what the treatment is. So, How to cure guppy ich? Let us find out.

Ich or white spot disease is caused by an external parasite in which your guppy gets white spots on their skin and gills. Treatment includes chemical treatment, salt and water method. Isolating new fish, plants, and invertebrates for 3-4 weeks is essential to prevent home aquariums from ich.

This article will discuss signs, treatment, prevention of white spot disease in the guppy, and more. So let us get into it.

What is ich?

Ich, also known as white spot disease, is caused by the ciliated protozoan Ichthyophthirius multifiliis.

There are three stages of an ich life cycle:

  1. A parasitic trophont
  2. A reproductive tomont.
  3. An infective theront.

These are the three development stages of ich.

A parasitic trophont lives in the host fish’s body, damaging the tissues and getting the fish into critical condition.

The host fish provide the parasitic trophont food and everything needed for their growth.

Then, when a parasitic trophont is matured, they leave the host body and attach to the tank’s side and bottom.

Now, the mature trophont produces a cyst wall to become reproductive tomont.

Every tomont gets divided by one cell to two, and the multiple division gets on.

A single cyst produces around a hundred to one thousand of infective theront.

Now, that infective theront leaves the cyst and swims in the water to attack the fish.

Once they find fish to attack, they start feeding on their tissue and become trophont. They feed on host tissue until they reach their matured size.

How to detect ich?

There are various signs you can look for to make sure that your guppy is suffering from white spot disease:

  1. Your guppy will have small white spots on their body.
  2. Guppy will scratch their body with rock or other objects present around them.
  3. You will see your guppy gulping air.
  4. Your guppy will have a sudden flashing behavior.
  5. Jumping out from the aquarium is also one sign of ich.

An owner should first detect the signs of white spot disease before starting any treatment.

We can be mistaken in detecting the white spot disease for other minor and not harmful problems.

For example, fin ray fractures look similar to white spot disease but are non-harmful for your guppies.

What are the causes of ich?

There are several causes of ich, and the most common cause is not being careful when adding a new batch of fish to the home aquarium.

An owner should not add new fish to the home aquarium directly from the pet shop.

Always keep the fish in a separate tank for at least ten days before adding them to your home aquarium.

It is essential because the parasite will not be visible to you in the early days, and your fish will also seem healthy and fit.

It takes time to complete a few life cycles of parasites, and when the cycle is completed, it will affect your guppy.

It will take a few days or weeks to complete a few life cycles of parasites.

So, it is essential to keep your new fish for some days in a separate tank and detect if they are suffering from such a parasite or not.

If you find any issues there, you should provide proper treatment to them.

Once you are sure that your new fish is healthy and does not carry any parasites, you can add them to your home aquarium.

The other causes of white spot diseases are:

  1. Using infected decor items like rocks in your aquarium without washing them before adding. 
  2. Adding infected water in the aquarium.

Treatment for ich?

An owner should first seek the vet for proper medication for better and fast recovery.

It is essential to know that you can be mistaken to identify the white spot disease.

There are other issues your guppy can go from that look very similar to white spot disease.

The other issues will need a whole different treatment.

Once the disease is identified, it will be possible to provide your guppy with proper medication treatment by your vet or pet store.

Regular monitoring and maintaining the water temperature is essential for killing the parasite from the system.

If your guppy is suffering from ich and is present in your home aquarium, first place your sick guppy in a separate tank.

And then run the treatment in both of the tanks as per the recommendation by the vet.

There are treatments for curing ich, including chemical treatment and salt and water:

Chemical treatment

Chemical treatment is challenging for a fish with a parasite attached to its body and gills.

Infected fish will not be able to tolerate the dose of the chemical which is needed to eliminate the parasite.

The best time to perform the chemical treatment is when the infective theront and the reproductive tomont are present in the water rather than the fish body.

Most of the anti-ich chemical present in the market contains a combination of malachite green and copper sulfate, or malachite green and formaldehyde.

You should place the infected fish in another tank to avoid treating chemical treatment to the healthy fish present in the tank.

A small hospital tank will require a small amount of chemical dose to treat your infected guppy.

Make sure to visit your fish vet to know the proper dose needed of anti-ich chemical for your infected guppy.

Salt and water

Adding one teaspoon of salt per one gallon of water in your aquarium and continuing it for five to seven days will eliminate the ich.

There are other methods like changing the water temperature and changing the water of the aquarium aquarist use to treat ich infection.

The lifespan of parasitic trophonts decreases with the increase of temperature.

So, slowly change and increase the water temperature of your guppy aquarium to 80°F and then slowly bring it back to the average temperature once the ich problem is resolved.

Increasing the water temperature to eliminate ich from the tank is controversial as an increase in temperature can cause stress to your guppy, and they can come into a critical condition.

But, this method eliminates ich disease from the tank, So you can perform this method with a recommendation.

How to prevent your guppy from ich?

To prevent ich and many other diseases and parasites from entering your guppies aquarium, all you have to do is isolate all new fish, invertebrates, and aquatic plants for some weeks before adding them to your guppies aquarium.

Whenever you buy new plants which were previously kept with fish, it should be the first isolate for at least two weeks before adding them to your guppies aquarium.

Keeping the plants separated from fish for some days will kill the parasites as they will not find any host to feed.

In such a way, keep all the invertebrates in a separate tank for two to three weeks before adding them to your guppies aquarium.

Once you successfully break the life cycle of parasites and are sure that there is no parasite present in plants, fish, and invertebrates, you can add them to your guppies aquarium.

The other things you should take care of for preventing your guppy from white spot disease are:

  1. Maintain adequate water condition.
  2. Provide your guppy with an appropriate diet.
  3. Regular maintenance of the guppies aquarium is required.
  4. Regular water change is important in case of keeping the water clean.

An owner should keep a regular check on their guppies to get familiar with their behavior.

And if you see any changes in their behavior and swimming patterns, you should take immediate action to treat them with medication.


Ich, also known as white spot disease, is caused by ciliated protozoan Ichthyophthirius multifiliis.

To prevent your guppy aquarium from ich disease, isolate all new fish, plants, and vertebrates in a separate tank for two to four weeks before adding them to your guppies aquarium.

There are treatments for ich, including chemical treatment and salt and water treatment.

But, we recommend you seek your fish vet or pet store first before applying any treatment to your sick guppy.

Reference: Britannica, University of Florida, Wikipedia, ResearchGate

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