Flowerhorn Diseases & The Best Treatments

Flowerhorns are well-known for their beauty, and the ‘kok’ or name associated with them is also a popular term in Feng Shui. The nuchal hump on this fish’s head gives it an extra charm that has made these creatures desirable to many over time.

These species are not naturally occurring but ones bred by humans over time and now live in wild populations. Generally, Flowerhorns survive in your aquarium for 10 to 12 years, adding color and life.

Logically, you will take great care of the fish throughout its life, but there is still a risk that the Flowerhorn will contract a disease. However, if you watch for the symptoms and take appropriate measures, you can easily treat them.

Here is a summary of what this article will cover:

  1. Most Common Flowerhorn Diseases
  2. Disease Causes and Treatments
  3. Preventing Your Flowerhorn from Getting Sick
  4. Maintaining a Healthy Aquarium Environment
  5. Proper Filtration
  6. Feeding
  7. FAQs

Related Flowerhorn Posts:

flowerhorn diseases

Most Common Flowerhorn Diseases

1. ICH (White Spot Disease)

When a Flowerhorn is infected with this disease, white spots appear all over the fish’s body.  Ichthyophthirius multifiliis (ICH), a ciliated protozoan, is the leading cause. Their behavior will also change, as they appear more sluggish than usual with fins clumped together. Decreased appetite is also a warning sign; you’ll find them in the tank’s corner.

There are a variety of causes for this disease, the most common of which is poor water quality. A decrease in water temperature below 25°C can also cause this problem. This disease can develop even if they have been fed frozen or live parasite-infested food.

2. Body and Tail Fungus

When the Flowerhorn is infected with this disease, a small white fungus grows on the fish’s body and mouth. Saprolegnia and other bacteria are the primary causes of this disease. This bacteria thrives in poor water quality. Also, if the water quality changes abruptly, this bacteria may flourish.

To identify this disease, look for symptoms like super soft tufts on the Flowerhorn’s body, mouth, and fins and weight loss. While this disease is curable, you must keep a close eye on the fish while it is sick. 

3. Popeye Disease

Popeye occurs with a slight bulging of one or both eyes, caused by fluid leaking into the area behind the eyeball. The protruding can become quite prominent as the condition worsens, leading to additional symptoms. Eyes may appear bloody, foggy, or blotchy if the swelling punctures the cornea.

The fish may also exhibit pervasive signs of anxiety, such as behavioral changes. A once-active fish now hides or stays near the tank’s bottom with a lack of appetite.

4. Dropsy

Dropsy can affect even the most stressed Flowerhorn. The digestive tract of a Flowerhorn is altered when infected with Dropsy, caused by a bacterial infection. If the water quality is poor and decorative items clog up, there’s a risk that the Flowerhorn will be affected by this disease.

5. Air Bladder Disease

When a Flowerhorn has air bladder disease, the air blade will not normally open, preventing it from swimming adequately. This is a severe problem that, if not resolved early, could prove fatal to the fish. Flowerhorn will not die from this disease but rather from its inability to swim properly. It becomes agitated and dies as it swims in the wrong position.

6. Digestive Blockage

Constipation is caused by poor digestion or an incorrect feeding technique. The involved fish’s abdomen appears to be bloated, and it is unable to defecate. Its belly expands as waste products accumulate, and the extra pressure on the fish’s abdomen causes discomfort.

Too much gas in the stomach or gut causes a fish’s abdomen to swell. Pathogenic bacteria cause gas production in the stomach and gut. As a result, we must administer a robust system of medications to restore the fish’s health.

7. Septicemia

Hemorrhagic septicemia is a highly contagious, life-threatening infection caused by the viral hemorrhagic septicemia virus (VHSV). It is generally carried about by an infected fish colliding with healthy fish.

The virus is usually spread through bodily fluids such as urine, sperm, or ovarian fluids. Any object in contact with these in contaminated water could become a virus carrier. Normal fish could contract the virus if they contact infected water.

Internal organ hemorrhage and skin and muscle bleeding are all common symptoms. External symptoms include bulging with reddish-colored bleeding around the eyes, inflated abdomens, and bleeding of gills, skin, and fins. The skin of some infected fish may have lacerations that appear darker in color.

Disease Causes and Treatments

Even if you strive to keep diseases from infecting your Flowerhorn, they are sometimes inevitable. You should be able to recognize diseases. If you do not understand and are not familiar with them, you may be unable to determine what is wrong with your fish and how to treat it.

When your Flowerhorn is infected with a disease, the first thing you should do is don’t panic. If noticed early enough, you can treat most diseases easily without losing your fish.

Preventing Your Flowerhorn from Getting Sick

An essential aspect of keeping a Flowerhorn is being aware of its disease’s warning signs. While feeding, you should keep a close eye on them.

Flowerhorn’s unusual behavior patterns, including its body language, will show you a clue that it is sick or has caught some disease. You’ll need to classify the disease in Flowerhorn and treat them carefully once you see the strange behavior.

Maintaining a Healthy Aquarium Environment

Water Temperature

You must provide a preferred water temperature for your Flowerhorn to establish a positive water environment. Flowerhorn thrives in temperatures ranging from 75 degrees to 82 degrees Fahrenheit. However, keeping the temperature between 80 and 85 degrees Fahrenheit is advisable. 

Water pH Level

Keep the Flowerhorn’s water at a constant pH level, between 6.0 and 7.6 are recommended. You can use a digital pH tester to monitor the pH of your aquarium water. This is because a drastic change in pH can be detrimental to the Flowerhorn.

Hardness Level

The alkalinity of the water is measured by its hardness. When it comes to Flowerhorn, it should be between 6 and 20 dGH.

Other Parameters

Meanwhile, the ammonia level in the water must be zero. And the Nitrate level in the water where your Flowerhorn will be kept should also be zero.

Proper Filtration

Flowerhorn requires a sufficient amount of oxygen in the tank. As a result, the proper filtration process on your tank will be required to circulate water. You must make certain that your tank is adequately bubbling. In the aquarium, the filtration process also aids in the removal of pollutants such as ammonia and nitrate.

A proper tank filter is one of the most important tasks in sustaining good water quality. There are so many various types of filters on the market. It’s crucial to pick one that’s right for the size of your tank and the number of fish in it. Additionally, you should clean your filter regularly.


Giving your Flowerhorn a healthy appetite will make them more robust. It’s advised if you only feed your Flowerhorn to its satisfaction. Flowerhorn will need to be fed 2 to 3 times per day. After 5 minutes, you’ll also need to collect all leftover food.

Providing a nutritious diet to your Flowerhorn is another excellent way to keep them healthy. This implies that you must nourish them with various foods, including live and frozen foods. Additionally, you should avoid overfeeding your fish since this can result in poor water quality.


What is Flowerhorn Hexamita?

Hexamita salmonis and Hexamita truttae are parasitic protozoa in the water that aggravate this disease, causing HITH or a hole in the head. This waterborne opportunistic organism plagues fish, particularly those with compromised immune systems due to overfeeding.

The disease is recognized by the Flowerhorn’s white feces and a reduction in the fish’s appetite. Striking holes in the head can also be seen from a short distance in the later stages of the disease.

Early Stage

Hexamita’s early stage, from the first to the third day, of infection, gives the Flowerhorn’s active and impulsive characteristics. Color concentration, pearls, and appetite are all normal. There are almost no symptoms of the disease except for one notable symptom.

You will notice a translucent, thick, white, string-like excrement with rounded beadings. This indicates that the parasite’s presence has agitated the fish’s intestines, causing the lining to shed.

It’s worth noting, however, that not all Flowerhorns with white, string-like excrement have a Hexamita infection. Flowerhorns usually lose their intestinal lining for a day or two when they encounter new tank water or a new diet. If the white, stringy poop persists for more than two days, your fish is likely suffering from Hexamitiasis.

Intermediate Stage

Agile mobility becomes increasingly rare during the fourth to the eighth day of infestation. The fish gives up its appetite and refuses to eat, and its vibrant colors fade. Due to the obvious body energy loss caused by no food intake, the fish swims less often and usually stays in one place. There’s also consistent intestinal lining shedding that causes the volume of its body to stay normal to slightly hyposthenic.

Terminal Stage

The infection is in its late stages after the 14th day. Because of the extensive shedding of the intestinal lining, the fish’s agility is severely limited. The parasite appears to have spread to the body cavity and the head, resulting in the widely recognized disease symptom of holes in the head.

Why is my Flowerhorn skin peeling?

Poor water quality, preceded by inaccurate water temperature and pH levels, is the most common cause. Stress, poor diet, and terrible tank mates are all factors that could cause skin peeling.

Poor Water Quality

Another causative factor in peeling is poor water quality. It can be triggered by a mixture of factors, such as overfeeding and improper tank cleaning. And the use of tap water containing chlorine or other contaminants.

Terrible Tank Mates

Goldfish and other aggressive fish are among the fish which are incompatible with Flowerhorns. If you have those fish in your tank, your Flowerhorn may become stressed and develop skin problems.

Water Temperature

Inadequate water temperature is the third leading cause of skin peeling. The water temperature for Flowerhorns should be around 78 and 84 degrees Fahrenheit. Skin problems can arise when the temperature is too low.

Poor Infiltration

This could also lead to poor water quality and skin irritations if you don’t have a good filtration system. A decent water filtration system will effectively protect the tank clean by removing harmful toxic compounds from the water.

Is aquarium salt good for Flowerhorn?

Table salt, sodium chloride or NaCl, is a beneficial preventative and treatment for various freshwater fish diseases. It facilitates wound healing, promotes the growth of slime coating, strengthens gill function, lowers osmotic stress, and works against a few external parasites.

However, some fish species and plant organisms cannot endure large amounts of salt, so you must use it cautiously. In these cases, conventional slime-enhancing products such as Stress Coat can offer some of the best benefits.

Why is my Flowerhorn turning GREY?

You don’t want to put your fish through unnecessary stress, as many variables can happen if you stress your fish. Their colors may fade, and their immune systems weaken, increasing their susceptibility to diseases and death.

So, what causes stress, you might wonder? Here’s a summary:

  • New tankmates, esp those who are abusive or incompatible
  • Overpopulation without enough hiding places
  • Water quality issues
  • Excessive illumination
  • Using of bright materials, decors, or backgrounds
  • The inconsistent temperature in the water
  • Poor nutrition and oxygen deficiency
  • Noise pollution

Flowerhorn Diseases Summary

Ensuring a clean and safe living environment with satisfactory criteria for your Flowerhorn is the first step in maintaining good health. It may harm your Flowerhorn if there aren’t enough natural resources, such as nutritious food, adequate temperature, and decent filtration.

Also, when a disease in the Flowerhorn is discovered, it is usually easily treated. Is your Flowerhorn active, or does it appear to be inactive? Once you notice weakness, you must investigate further to see if there are some other symptoms.

Leave a Comment

Your email address will not be published.