Flowerhorn Diseases and Treatments [2021 Guide]

Flowerhorn cichlids are one of the ornamental aquarium fish. Flowerhorn fish are noted for their vivid colors and as well as for the distinctively shaped heads “Kok.” These fish are named as Flowerhorn because of their head. These fish are man-made hybrids like blood parrot cichlids. And they are found in the wild only because of their release. Today in this article I am going to give you a brief introduction on flowerhorn diseases and treatments that you can perform easily.

The most common diseases that the flowerhorn fish suffers from are Hole In The Head (HITH), ICH(White Spot Disease), Fin and Tail Rot (Columnaris Disease), Popeye Disease, Bloat Or Dropsy, air bladder disease, internal parasite or digestive blockages, and Septicemia.

The Flowerhorn was first developed in Malaysia, then in Thailand and Taiwan during the year 1993. These fish became very popular among the Asian fish keepers. These fish are also kept by American fish keeper in the United States and as well as in Europe, but are banned in Australia. The lifespan of Flowerhorn is about 10 years to 12 years. Flowerhorn fish require a water temperature of 80 degrees Fahrenheit to 85 degrees Fahrenheit. Flowerhorn is a big fish, so it requires a tank with a minimum of 55 gallons for a male Flowerhorn, depending on its size.

This article will help you to learn about some of the most common Flowerhorn Diseases and Treatments.

You should always set up an aquarium for Flowerhorn fish the right way as the right water parameter, and the right tank’s environment is the key to healthy flowerhorn fish.

Flowerhorn Diseases and Treatments

Prevention Is Better Than Cure:

Always Wear a Protective Mask when you go out. Its better to use a N95 Mask.
Always Wear a safety Goggles.
Make Sure you Wash your hand with a soap for at least 20 Seconds.
Carry A sanitizer when you go out.

Flowerhorn Sickness Prevention

Flowerhorn and other fish are also like human beings. They also get sick and get diseases. And to cure these sicknesses, you will need to take care of your fish. Usually, people think caring fish is just feeding them 2 to 3 times a day, but that is not enough. Caring also includes maintaining water qualities. It is also as important as feeding them daily. Fish also have a feeling like a human; you need to care for them like a human.

The most important thing about keeping a Flowerhorn fish is to pay attention to the distinctive sign of diseases of the Flowerhorn. The fish keeper should observe their pet, Flowerhorn, carefully while feeding them. This will give us, hobbyist, a hint that Flowerhorn is sick or it has some diseases from its strange behaviors and as well as from its body languages. Once we get to see the strange behavior, we will need to identify the disease in Flowerhorn and treat them with care.

Now that you have understood the diseases and treatments, if you want to prevent the sickness of your Flowerhorn and keep them healthy, then you will just need to follow the following instructions.

Flowerhorn Water Parameters

The water parameters help to identify the suitable properties of water for specific species that will maintain the quality of the water. Especially for an aquarium environment, the water parameters play an important role because it consoles the welfare of the fish and other species within the tank. Commonly measured water parameters include the pH level, temperature, hardness, ammonia level, nitrite level, etc. You should be able to manage the proper water condition for your Flowerhorn.

Flowerhorn Water Temperature

In order to create a favorable water environment for the flowerhorn fish, you should provide a preferable water temperature. The temperature needed by the flowerhorn tetra is similar to other tropical fish.

Flowerhorn grows well in the temperature between 75 degrees Fahrenheit to 82 degrees Fahrenheit. However, we would recommend you to keep the temperature between 80 degrees Fahrenheit to 85 degrees Fahrenheit. 80-85 Degree Fahrenheit is the best temperature to keep your Flowerhorn healthy.

Likewise, keep a heater and an aquarium thermometer to monitor your aquarium’s temperature. Here are my top picks, which I use in my aquariums.

MarsAqua Dimmable 165W 300W LED Aquarium Light

Hygger Saltwater Tank Titanium Tube Submersible Pinpoint Aquarium Heater with Digital Thermostat

Fluval E Electronic Heater

Water pH Level

You should be able to maintain the pH level of the water where the Flowerhorn lives. We recommend you to maintain the pH level of water from 6.0 to 7.6

You can use a digital pH tester to monitor your aquarium water pH. The drastic change in the pH level can be harmful to the Flowerhorn. If you really wish to keep your Flowerhorn healthy, then you will need to check the pH level of water periodically. 

Hardness Level

The hardness measures the alkalinity of the water. In the case of flowerhorn, the alkalinity should be within the range of 6° to 20° dGH.

Other Parameters

Similarly, you will need to maintain the ammonia in the water at 0, and the Nitrate should also be 0 in the water where you are going to keep your Flowerhorn. For this, use Ammonia Tester, Nitrite Tester, and Nitrate Tester. Alternatively, what you can do is, you can buy a master test kit that has several other water test kit inside the package.

Always Use: API Freshwater Master Test Kit

Maintaining Water Quality

The quality of water is very important for any aquatic species. Just as the air we breathe should be pure and free of contamination to avoid many diseases, the water quality aids the fish to feel secure in their habitat. Few of the ways from which you can maintain the water quality are mentioned further:



Flowerhorn needs enough Oxygen running in the tank. Therefore, you will require the proper filtration process on your tank to circulate water. You will need to be sure that your tank is sufficiently bubbling. The filtration system also helps in pollutants like ammonia and nitrate in the aquarium. The filtration process helps in the nitrogen cycle of an aquarium. 

There are various filtration systems and filtration methods you can choose. However, for filtering a bigger aquarium, what I found the best method is to use a sump filter. A sump filter is an aquarium filter that uses baffles and includes a variety of filtration media in it. However, if you do not have enough room in the cabinet of your aquarium, I recommend using external canister filters. A canister filter is a great replacement to the aquarium sump filter.

Best Filter for Flowerhorn tank:

Fluval FX4 Filter w/Biomax, Filter, Bio & Carbon Foam & Filter Media

Hydor Professional External Canister Filter – Aquarium External Filter

Marineland Magniflow Canister Filter for Aquariums, Fast Maintenance

Water change

Water change is one of the most important factors in caring for your Flowerhorn. Your Flowerhorn will not like to live in a dirty environment, so you will need to change the water. You will need to change 25% – 30 % of the water on a weekly basis. This will help you to keep your Flowerhorn healthy and disease-free.

Water changes are very essential for the good optimization of water. Because, no matter how much good filtration system you use, since your aquarium is a locked ecosystem, the dirt and waste will pile on. This will encourage various pollutants to develop and affect your fish if you do not take care of it. 

The Python 25 ft. No Spill Clean & Fill can work with your faucet to siphon water from your tank directly into the sink, making water changes a breeze. However, if you choose to not use the faucet to create siphon, you can use the included Stressless Siphon Starter to create siphon. It also can refill the tank with water from the faucet (freshwater only) for ultra-quick water changes. -Amazon.


The other most important factor is feeding. A healthy appetite will help you Flowerhorn to be healthy. You will need to feed your Flowerhorn up to only they can consume. You will need to feed Flowerhorn 2 to 3 times a day. And you will also need to pick up all the left-over food after 5 minutes.

Best Food For Your Flowerhorn (For both the color and head size):

Freeze Dried Brine Shrimp Cubes

Omega One Super Color Cichlid Pellets Small Sinking

Ocean Free Set 120 g Humpy Head Ever Red Size M Pellets Xo Flowerhorn Fish Food

OKIKO Fish Food Set L Pellets of 3 Quick Red Mark Head Up Huncher Platinum Huncher and Color Faster Cichlid Flowerhorn

Automatic Feeder: Eheim Automatic Feeding Unit

Flowerhorn Diseases and Treatments Guide

Even if you try your best to avoid the diseases that might occur in your flowerhorns, sometimes the diseases are inevitable. When any diseases affect your flowerhorn, the first thing you do is to not panic. Most of the diseases if you catch them early, you can treat them easily without losing your fish. 

However, you should recognize the diseases because if you do not understand and know the diseases you might not know what is wrong with your fish and how to treat them. 

Here are the different types of diseases that may occur in your flowerhorn along with their treatments. Keep reading for more information.

Flowerhorn Whitespot Disease

As the name suggests, when your flowerhorn is suffering from this disease you can see the white spots all over them. It looks like someone sprinkled salt all over the fish body. The fish may not want to eat and mostly stay cluttered in the corner of the tank. They may scratch their body against hard objects, decorations, or gravels.

The cause of this disease is a ciliated protozoan called Ichthyophithirius multifilis (ICH). Bad water quality can increase the risk of ICH. Additionally, the temperature below 25 Degree Celsius is the ideal temperature for the ICH to breed. Sometimes, you might unknowingly feed your Flowerhorn live or frozen food that is contaminated with ICH.


  • The cause of this disease is a ciliated protozoan called Ichthyophithirius multifilis (ICH ).
  • Bad water quality can increase the risk of ICH.
  • Temperature below 25 Degree Celsius is the ideal temperature for the ICH to breed.
  • Feeding you Flowerhorn live or frozen food that is contaminated with ICH.


  • Clearly defined small, pure white spots.
  • It looks like someone sprinkled salt all over the fish body.
  • A loss in apatite, fins may be clumped.
  • They may scratch their body against hard objects, decorations, or gravels.


  • To treat this, you will need to change 75 % of the water,
  • Immediately add water treatments like Aquarisol plus 1 tablespoon salt per 10 gallons.
  • Raise the water temperature little more than 85 degrees Fahrenheit for a couple of days.
  • Do 50% water change daily, and treat the whole tank once the fish is cured.


  • Always quarantine newly purchased fish for 3 to 4 weeks.
  • Need to do lots of water change.
  • You will need to avoid the cross tank contamination

Medicine for Ich

King British Methylene Blue

API Aquarium Salt

Seachem ParaGuard


Flowerhorn Hole in the Head Disease

One of the most dangerous diseases occurring in flowerhorns, which can cause their death, is the hole in the head disease. You can know this disease as Hexamita. However, if you can identify the disease sooner, you can get a chance of treating it.  

You will find small pits and pimples grow in the fish head. These pimples will keep on growing with time. Also, small grayish worms crawl out of their head region. The fish stops eating, loses weight, dark coloration, head standing, dark coloration, clamped fins.

The Hole in the Head, HITH, is caused due to Hexamita Protozoa, which is highly contagious. There will be high chances that your flowerhorn can catch this disease is when your tank has poor water quality.


  • You will need to change 75% of the water from your tank.
  • Add 250 mg of Metronidazole per 10 gallons of water.
  • To make it more effective, your fish will need to be forced to feed using a syringe.
  • Repeat the treatment once every 2 to 3 days, until cured.


  • We will need to change about 10-20% of the water once a week.
  • Need to quarantine doubtful looking fish.
  • Maintain the water temperature.
  • Avoid cross-tank contamination.

Medicine for Hole In The Head

API MELAFIX Fish remedy

Flowerhorn Fungus Disease

The fungus disease will occur around the flowerhorn’s mouth, body as well as tail. You can notice small white fungus growing on the fish. The Flexibacter Bacterium causes this disease in the flowerhorn. These types of bacteria thrive in poor water quality and through a sudden change in water conditions.

You can check for few symptoms such that a loss in apatite, fish’s fins, and tails will start getting shorter, and the white or grayish cotton wool-like thing will grow on their skin, mouth, and fins.


  • Mouth-Body Fungus is caused by the Flexibacter Bacterium.
  • The bacteria thrives in poor water quality.
  • A sudden change in water condition.


  • A loss in apatite.
  • Fins and Tails will start getting shorter.
  • The white or grayish cotton wool-like thing will grow on their skin, mouth, and fins.


  • You will need to do a frequent water change.
  • Need to quarantine infected fish.
  • Various water treatments must be used like Methylene blue, Acriflavine, and many more.
  • Add 1 tablespoon aquarium salt per 5 gallons of water
  • Raise temperature to 80 to 80 degrees Fahrenheit.
  • Treat with Metronidazole or Fungus care.
  • Do 30% of water change every three days and repeat the treatment.


  • Need to do a frequent water change.
  • You will need to avoid cross tank contamination.
  • Always need to quarantine doubtful looking fish.

Medicine to Cure Fungus

API Melafix Fish Remedy for Bacterial Infection in Freshwater Aquarium

API PIMAFIX Antifungal Freshwater and Saltwater Fish Remedy

King British Methylene Blue

Flowerhorn Flukes

This disease is commonly known as gill flukes as there will be the development of worms in the fish’s gills. When this happens, the fish will continually scratch themselves on the rocks and rough surfaces. The Gill plates of the fish will be closed tight or not even functioning during breathing. This will cause the fish to suffocate. 

Most of the gill fluke occurs in your fish when you add a new fish inside the tank. The water condition also plays a great role in affecting the fish with this disease.


  • Fish will continually scratch themselves on the rocks and rough surfaces.
  • Gill plates of the fish will be close tight or not even functioning during breathing.


  • We will need to do 75 % of the water change.
  • And treat the tank with the formalin.
  • We will need to wash all the filtration equipment.


  • Need to do lots of water change.
  • You will need to avoid cross tank contamination.
  • Always need to quarantine doubtful looking fish.

Flowerhorn Dropsy

Dropsy affects the digestive system of a flowerhorn. Unable to take care of it at an early stage, the health of the Flowerhorn may present a certain serious concern.

The main cause of dropsy is due to bacterial infection of your internal fish organs. However, as I have stated many times, the quality of water affects the development of diseases directly. The tank often has decorative products overcrowding and stressing the fish can cause this disease

For identification of this disease, you will get to see excess body fluid, which builds up inside the fish. The eyes and scales are swollen more than normal. There will also be loss of appetite and the fish may appear bloated.


  • Caused due to bacterial infection of your internal fish organs.
  • Poor water quality
  • Overcrowding and stress can cause this disease


  • You will get to see excess body fluid, which builds up inside the fish.
  • Eyes and Scales are swollen more than normal.
  • Will stop eating food.
  • The fish may appear bloated.


  • Commercial treatment is available at your local fish store.
  • Act as soon as possible since this disease can kill your fish.
  • Never use aquarium salt while treating dropsy; this will kill your fish in a short time.
  • You will need to use Tetracyclin, Maracyn, Kanacyn, or broad-spectrum antibiotic foods, commercially prepared treatment available at your fish store.


  • Need to do lots of water change.
  • You will need to avoid cross tank contamination.
  • Always need to quarantine doubtful looking fish for 3 to 4 weeks.

Medicine for Dropsy

API FIN & BODY CURE Freshwater Fish Powder Medication

King British Methylene Blue

FlowerHorn White Poop Disease

White poop disease is one of the most common diseases that a Flowerorn Fish suffers from. The disease is also known as White Stringy Feces Disease where the fish excretes white stringy sticky poop. When you fish suffers from white poop disease the fish may have swollen belly or stops eating the food. Hexamita, an internal parasite is one of the main causes of this disease. 

Additionally, when you feed flowerhorns frozen and live foods can increase the possibility as well. Another factor can be the poor water quality of the tank. The high protein diet can also cause the growth of worms inside the fish.

You may notice a great loss in apatite. Flowerhorn fish starts affected by this disease might start pooping white sticky material.

Let us look closer at the causes of symptoms and treatment of the disease.


  • Internal parasites inside the fish stomach cause this disease.
  • Frozen and live feeding.
  • Poor water quality.
  • The high protein diet causes the worm inside the fish grows.


  • A loss in apatite.
  • Fish starts pooping white sticky material.


  • Use CLEAR medicine by Aqua Product or OCEANFREE WHITE POOP for the treatment.
  • Increase the temperature of the water above 30 Degree Celsius.
  • Keep your fish without feeding for three days.
  • Remove at least 30% water on the third day.
  • Repeat the treatment until fish is healthy.
  • Feed the fish with a low protein pallet.


  • Maintain your water quality.
  • You need to do a regular water change.
  • Move your sick fish to a hospital tank.

Medicine of White Poop Disease

Clear Medicine For FlowerHorn Fish for Treat white pooh and inflammatory bowel by CZ Aqua Products

Dr. Tim’s Aquatics Natural Aquarium Products, Freshwater

Hikari Usa AHK73254 Prazipro for Aquarium

Flowerhorn Swollen Eyes

The swollen eyes are also called a pop-eye or cloudy eye. This disease is the manifestation of dropsy. Tissue fluid leaking into the area behind the eyeball causes the swelling of the fish’s eye. The volume of fluid increases as the pressure builds up, pushing the eyeball of the fish outside. There are usually occasional bacterial infections. The cloudiness of the fish’s eye is caused by corneal damage (the pupil’s translucent skin layer).


  • There should be a hospital tank. It is the most appropriate 10 or 20-gallon tank. You should not use a smaller tank, as it only stops fish from moving and can worsen the problem. The suggested size is 20 gallons tanks.
  • The antibiotic, tetracycline-class is required. Dissolved in warm water and blend in a tank of 500 mg of tetracycline (or doxycycline).
  • Use AGED WATER to make a 100% change of water every 2 days! Substitute antibiotic. Follow step 2
  • Use a heater for the aquarium and position it at 32 ° C.
  • 2 weeks minimum therapy time.
  • Methylene blue should be put in fungal infection tank water. When the fish is at that phase.

Flowerhorn Skin Peeling

Flowerhorn fish have a habit of scratching themselves through hard surface, such as gravels, rocks, decorations, and your aquarium walls. When they do this, there is a high chance of them getting hurt due to the peeling of the skin.

These wounds can get worse when it is not taken care of properly. You need to check if the wound is healing timely or not. If it is not then you have to take necessary actions.  From these wounds, the skin of the flowerhorn can start peeling. 

When this happens, you have to make sure that the water quality is very high in order to prevent the wound from any further infections.

Bloating Diseases

Another disease that you can find in your flowerhorn is the bloating disease. The fish seem to be somewhat bloated and it often seems like they are struggling to balance themselves, because of excessive growth.

The key cause is the feeding of starchy foods to the fish that makes it difficult to produce gas and expulsion. Bacterial infections, impaired swimming bladder, complications of congenital growth, sudden traumas, and stress are other factors.


  • Food that is high in fiber. The use of Lactobacilli acidophilus by gel foodstuffs leads to the removal of GI water. A few days’ fasting helps to remove the foods that are not digested from the gut.
  • API Melafix and aquarium salt should only be given if the root cause is diagnosed correctly.

Flowerhorn Avoiding Food

If you are following all the diseases mentioned in the above section of the article, there are many symptoms where your flowerhorn can lose their appetite. The main cause is the disease and stress caused by diseases. 

Whenever the fish feels uncomfortable in their own environment, you can see them avoiding food. There can be parasitic fungal development within the fish’s body as well.

You can use medicine such as Ocean Free Anti chlorine or Ocean Free Gill Fungus Parasite Special.


  • Adjust the water entirely and add it to the tank.
  • Fold 1 cap into a tank of Ocean Free Antichlorine.
  • Apply 1 cap to the unique tank of Ocean Free Gill Fungus Parasite.
  • Connect the heater to 28′′ c.
  • Fill the tank with water.
  • Start feeding flowerhorn after two days.

Flowerhorn Head is shrinking

Now, there can be a number of reasons as to why your flowerhorn’s head is shrinking. Some of the reasons might be stress, ICH, degrading water quality, having a large amount of chlorine in the tank water, Hexamita, etc. 

You can avoid this simply by regularly maintaining the water changes schedule. Keep in mind to check the chlorine amount in the water. Moreover, you can give the flowerhorns the necessary medicines and diet. However, do not ever overfeed them because the flowerhorns can eat as much as we let them.

Healthy foods that contain a high level of proteins are very important for their head to grow. Make sure that the health of the fish is of the utmost priority and the water of the tank is clean. About 30% of the water changes every week is necessary. In addition to that, also look after the water parameters as the fluctuations in them can cause stress in flowerhorns. 

What are Flowerhorn Stress Marks?

As stated previously, flowerhorns are very much prone to stress. You can identify a few behaviors as signs of stress. Apart from that, Flowerhorns are unique, incredible, and colorful fish that can show you how they are feeling. They do this by changing their colors. 

This phenomenon is commonly called stress color or stress marks. The colorful bodies of the flowerhorn can turn into very pale colorations of white, grey, black, etc. Some of the stress colors are:

  • Vertical black stripes 
  • All white body 
  • All dark body 
  • Faded black spots (the flowers)

The cause of the stress mark can be adapting to the new tank and water conditions. 

Flowerhorn Stress Treatment

Before you act on the stress treatment of your fish, first you need to understand the cause of the stress.  There are many causes of stress in the fish. You might feel it strange but fish also stresses just like us humans. Few reasons for stress in the fish can be improper water conditions, problems with other fish, presence of toxins and impurities, improper diet, etc. 

There is no need to alarm yourself because simple solutions can help your fish to feel better. Few of the steps include:

  • Change the water regularly to maintain low levels of nitrate and ammonia. Consider adding water conditioners such as the API stress coat, which is designed to reduce stress on fish by 40% by eliminating contaminants that are toxic. Or try API Stress Zyme Water Conditioner, which cleans your aquarium and enhances its natural cycle.
  • To prevent unpredictable fluctuations, test water temperature for consistency periodically.
  • Provide an effective filtration device such as Penn Plax Cascade 1000 Canister Filters for collecting bacteria and debris while ensuring proper oxygenation.
  • Adjust the temperature of the water and make sure your present fish get used to their new filler mate by introducing new fish correctly, preferably by immersing them in a tank while they are still in their plastic bag.
  • If you encounter abuse, remove the attacking fish and put it in a separate tank.

Prevention Is Better Than Cure

Now, if we are to travel some area that is different from our daily habitat, we take precautions so that we do not get ill. The same concept with the fish you have in your tank. 

You will need to maintain the water parameters daily and check the telltale signs of any diseases your fish might be suffering. Maintaining the water parameters and regularly performing water changes is essential for your fish. This is beneficial because particular fish will have a specific range of parameters that they can tolerate. If the water is not of high quality then there can be the development of toxins such as ammonia, which leads to many diseases in the fish, even resulting in their death.


Hence, from this article, I hope you are well aware of the different diseases that can occur in your Flowerhorns. Make sure you catch these diseases timely and treat them carefully. Remember that the flowerhorn diseases are common and the treatments is also easy if you understand it.

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