How To Treat Ich In Fish – Symptoms, Prevention, & Treatment

For an aquarium owner, parasites and diseases are a nightmare. It can kill all the fish in the aquarium if left untreated.  One type of common disease in an aquarium is ich!  Ich, also known as “white spot disease” or “ick”.

Unfortunately, there’s no way to prevent them entirely from infecting the aquarium.  In this article, it will give you all the details about this parasite and how to treat ich in fish.

What Is Ich?

Ich (Ichthyophthirius multifiliis) is a parasite infection. This parasite is present in all aquariums, small and large ones.

There are no ways to get rid of them completely as they live among the plants, substrates, and even on the fish!

Fish have a strong immune system that helps fight diseases and other pathogens. When the fish’s immune system weakens, it could be due to stress or other reasons, they are vulnerable to an attack from ich.

Symptoms Of Ich

The most common symptom for ich is the white spots found all over the fish body. The white spots that you see on the fish are where the parasites have nested.

The white spots on the body of the fish are usually about 1.5 mm (3/64 inch) big. From a distance, they look like grains of sugar that have been stuck on the fish.   It usually appears small spots, but there are some cases where the spots may be larger or clump together.  The white spots will usually appear all over the body of the fish, from the mouth to the tail fin.

As you examine them closer, you’ll see it’s actually small holes on the gills, fins, and skin of the fish.

While the main symptoms are the white spots all over the fish body, there are a couple of other symptoms you can look for in the fish when it has ich.  Below are some other symptoms affecting fish with the parasites.


The fish will begin to lose weight due to loss of appetite. The fish may not eat even when their favorite food is present. In addition, they could go an entire day without eating anything.

Cloudy eyes

This is one symptom ich is present on the fish. However, this symptom can be from other things such as poor water quality, injury, stress, or just old age. For that reason, you should further investigate what’s really causing the cloudy eyes.

Rapid breathing

When the parasite is present in the gills of the fish, oxygen is limited from being absorbed in the blood. This will cause the gills to rapidly move to increase the circulation of the oxygen. The fish may also spend a lot of time going to the surface of the water gasping for air.


Ich presented on the fish causes skin irritation. To try to stop the itching, they will rub themselves on aquarium glass, decorations, and ornaments.

When a fish is rubbing against something, this is also referred to as flashing. This is normal for fish to do, but when it’s excessive flashing, it’s a telltale sign of ich.

How To Treat Ich In Fish

Ich can be found in both new aquarium setup and established aquarium.   For these parasites, it doesn’t matter how old the aquarium is, it’s just waiting for the right condition to start infesting the aquarium and infecting the fish.   Once they do, there are a couple of ways to treat ich and kill them in the aquarium. Below are some effective ways to treat ich in the aquarium.

Raising Water Temperature

To get rid of ich, raising the temperature of the tank is very common. The idea behind this is to speed up the progression of the whole progress. The higher temperature will help move the ich through its life cycle fast, which in turn, helps the fish recover from the infection faster.

The ideal temperature to get rid of ich is about 82 degrees Fahrenheit.

The temperature should be raised for about 2 days, but it’s recommended to keep the temperature steady for 4 days total to get completely remove all ich from the water.

Using Salt To Treat Ich

Salt treatment is also very effective at killing ich in the fish tank. With the salt treatment, the fish doesn’t need to be removed from the tank.

However, you’ll want to be careful with fish that may be sensitive to sale. Fish that are sensitive to salt are loaches, discus, and tetras. These fish may experience a bad reaction to the salt. If they do have an allergic reaction to it, the fish will begin to breathe rapidly or have clamped fins. When this happens, a quick water change to remove the salt will help return the fish to normal.

On the other hand, other fish such as the goldfish, mollies, swordtails, and guppies react to the salt treatment well.

To do the salt treatment in the fish tank, you’ll need to make sure the fish indeed have ich. Once this is confirmed, make sure you have salt ready. The type of salt used can be table salt or sea salt. Start with a half dose of salt. After about twelve hours, add another half dose of salt to the fish tank.

A full dose is one tablespoon per five gallons of water.

For example, if you have a 50-gallon fish tank, you’ll want to start with 5 tablespoons of salt. After twelve hours, add another 5 tablespoons of salt. Repeat the salt treatment for 2 days or 48 hours.

After 48 hours, do a 25 percent water change. This is to ensure the water is not too diluted with salt. After changing the water, add a full dose of salt to the water.

Repeat the process two more times and the fish tank should be free of ich.

Using Garlic To Treat Ich

Unknown to most aquarium owners, garlic is an effective treatment again external parasites, especially ich. Garlic is not only effective at killing the ich in the fish tank, but it’s also safe for all fish as well.

The most powerful component of garlic is the chemical it contains. This chemical is called allicin. Allicin has the power to actively and directly kill parasites including ich.

When using the garlic treatment, it’s best to use freshly pressed garlic. It’s the most effective at killing the ich.

To use garlic, press the garlic until the juice drain from it. Mix the garlic juice with fish food and feed it to the fish.

If you’re not into pressing garlic, you can buy the garlic treatment, Thera+A formula, which can be found on Amazon. It contains enough garlic to kill parasites. It comes in a wide range of sizes, which makes it ideal for all different types of fish.

Total Fish Removal

The last option is to remove all the fish from the aquarium. This is a great option when the tank is too large to treat the volume of water.

When the trophonts have infected and fed on the fish, it will be ready to leave when it’s full. When it leaves the fish, it develops into a tomont. The tomont will drop to the bottom of the aquarium where each tomont is capable of producing several thousand theronts. At this stage is where you need to get rid of all the parasites.

When all the fish are out of the tank, raise the aquarium temperature to 80 degrees Fahrenheit. Keep it at this temperature for about 2 days. The tomites will die in the absence of fish. To be sure that all the tomites are dead and the aquarium free of the parasites, some recommend keeping the tank empty for 2 more days with the temperature still at 80 degrees.

Prevention Of Ich In Fish

Ich exists in all aquarium and there’s really no surefire way to prevent them.  However, there are some ways in which you can help prevent ich from appearing and infecting the fish in the fish tank.  Remember, these parasites need the right water condition and a fish weak immune system to start infecting them.  Below are some effective ways in which you can help prevent ich from infecting the fish.

Quarantine New Fish

The best way to prevent ich from happening is to quarantine all new fish in a separate tank before putting them in the main tank.  Leave them in the tank for about 4 weeks.  During this time, if the fish do have ich, you are able to treat it right away.  Doing so will prevent the ich from spreading to other fish.

Treatment For New Plants

Aquatic plants that you’ve just bought or got from a pond outdoors may carry ich cysts.

The best way to prevent them from occurring in the aquarium is to treat the plants first. All you need to do is put the plants in a bucket of water and treat the water with ich medications.  Keep the plants in there for about a week and it should kill the parasites if it exists.

Maintain High Water Quality

It’s uttermost important to maintain high water quality in the fish tank.  This means the aquarium filter should be changed as scheduled and do water changes when needed.  If not, the water quality will be compromised and ammonia and nitrates level will increase.  This will lead to low-quality water which will make the fish sick.  When the fish get sick, their immune system is weak and this is when ich starts attacking the fish.

Prevent Stress

Ich is present in all fish tank and they don’t start attacking the fish until the fish’s immune system starts to weaken.  Stress is one factor that contributes to a weak immune system of the fish.  Some of the stress can be from an incompatible tank mate, an illness, low-quality food, loud sound, or bad water quality.  There are many other things that could cause the fish to be stress.  For that reason, it’s important to find what’s stressing them and fix it if possible.

Provide Fish With A Well-Balanced Diet

Fish that are fed low-quality food or not fed a well-balanced diet, will result in a weak or sick fish.  When the fish is sick, their immune system will weaken and this is when the ich will start to attack the fish.

Fish like Cory catfish needs to eat a well-balanced diet because these species of fish are prone to ich.


The best way to stop ich from infecting the fish is to prevent it from happening in the first place.  This means being cautious about the fish you’re buying.  Most of the time, ich happens from fish that are bought in the pet stores.   Due to fish being moved in and out of tanks often, there will be ich and other parasites in the water.  Before putting the fish you’ve just bought in the tank with other fish, quarantine them first and treat them for ich and that should prevent your fish tank from having ich problems.

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