Flowerhorn Without Hump – Why Flowerhorn Won’t Grow Kok?

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Flowerhorns are known and appreciated for their huge forehead humps, also known as koks. These bubble-like growths give the fish a unique appearance. In recent years, such fish has become something of a statement piece in the aquarium.

But sometimes, Flowerhorn cichlids don’t have that fancy signature hump. This is completely normal. Not all members of the species can grow a kok.

Some are late bloomers and might take longer to reach their full growth potential. Keep reading to figure out which category your Flowerhump falls into!

In this article, I’ll cover the reasons why Flowerhorns sometimes can’t grow a kok. I’m also going to include some tips to maximize your fish’s growth potential.

But first, let’s get a better understanding of where this hump comes from.

Why do Flowerhorns Grow a Kok?

The simplest answer to this question? They do so because we wanted them to. Flowerhorn cichlids are specifically crossbred across generations for their specific look.

In East and Southeast Asia, where this species was created, a fish with a big hump is considered a token of good luck.

So these features were desirable enough to bring us the charming Flowerhorn. This unique-looking fish has three parent species— the Red Devil Cichlid, the Trimac cichlid, and the Blood Parrot Cichlid.

Naturally, each of these species has a noticeable head hump. But it’s nowhere near the size and shape of a Flowerhorn cichlid’s.

Still, by looking at these species, we can better understand the natural mechanism behind the Flowerhorn’s bulging forehead. In these species, the nuchal hump (also called “kok” in Flowerhorns) is mostly made up of fat and some water.

It is believed that in the wild, a fish with a big hump has a higher chance of survival during periods of scarcity.

The extra fat stored in the hump will keep the fish’s energy levels up during the mating season and when there’s not enough food to go around. The hump might also be a way to show dominance and attract mates.

The same is true for Flowerhorns. It’s usually the males who grow a noticeable kok.

More dominant males usually have the largest koks. This is perhaps because they get the most food, so they store more fat than other fish. Either way, it seems like size matters for these fish species. The reverse is also true. Less well-fed fish or fish that experience a lot of stress will have smaller koks.

Do Female Flowerhorns Have Hump on their Head?

The difference between a male’s and a female’s hump size and shape are quite drastic. For this reason, people usually say that only male Flowerhorns grow a hump. But this is a load of bologna. If we’re to get technical, then females also have a hump.

It’s just not the same as a male’s. If you see a Flowerhorn with a massive, bright-colored hump, it’s guaranteed to be a male. Females, on the other hand, have very subtle humps, more similar to those of cichlids you’d find in the wild.

Genes also play a role in the development of the hump. Some male fish might have very small humps, similar to a female’s. Sometimes, although rarely, females can also develop slightly larger humps.

Still, the size of the hump remains a distinguishing characteristic between male and female Flowerhorns.

Why Doesn’t My Flowerhorn Have a Hump?

Multiple factors play into the development of a Flowerhorn’s hump. If your fish has a tiny forehead, it may simply have poor genes. Genes will determine the fish’s potential to grow a big nuchal hump.

If all other factors are taken care of, and the fish is still not developing properly, maybe the big colorful bump was never meant to be.

You need to do your research when purchasing Flowerhorn fish because not all breeders are equally experienced with cross-breeding and selective breeding. Another reason why your fish might not grow a kok?

Maybe your fish is actually female. Wrongly sexing fish is a common mistake. It happens to the best of us, even the well-versed fishkeepers!

I don’t recommend venting your Flowerhorns though. It’s not like the sex of the fish matters too much, since this species is usually infertile. Perhaps your fish are also simply too young.

Early bloomers might start developing a hump as early as they reach 2 inches in size. For others, it might take a few extra months.

Some fish don’t start showing a prominent hump until they’re around 4-5 inches long. If your fish is at least 5 months old, and confirmed male, there might be other things halting its development. Stressed or poorly-fed fish develop slower. Luckily, there are steps you can take to aid your Flowerhorn’s development. We’ll cover these later in this article.

When does a Flowerhorn Start Growing Its Hump?

There’s no exact moment when a Flowerhorn should start developing its hump. This depends on the fish’s genes.

Some are early bloomers, while others might take a bit longer. But for all Flowerhorn fish, the transformation happens early in life.

If the fish doesn’t show any sign of a growing hump by the time it’s 5 inches in size, it’s safe to assume it will never grow one.

Also, not all male Flowerhorns can develop a hump. You never know what you’re going to get when buying Flowerhorn fry.

If your fish have good genes, you’ll see early on. Some fish develop a noticeable kok as soon as they reach 1.5-2 inches. Most fish however will start growing a hump at around 3-4 inches. It will also depend on the species. Some grow slower than others.

On average, a Flowerhorn cichlid might grow a little less than 1 inch per month. So, if you bought a few juveniles, you should wait at least 3-5 months before the first signs of growth. If your fish are already 5-6 inches long, it’s highly unlikely they’ll grow a hump at this point.

How to Grow Flowerhorn Hump Faster?

Not all fish might have the genes to grow a massive hump. But there are still things you can do to make the best out of what you got.

The following tips will help you maximize any Flowerhorn’s growth potential. They also help keep your fish healthy and happy, so it’s a win-win.

Here are 6 tips to help your fish grow its hump faster:

1. Maintain A Clean Tank

The health and growth of your fish are closely tied to the health of its environment. Unsanitary conditions lead to stress, health problems, and even death in fish. That’s why I recommend larger water changes.

To keep the tank in pristine conditions, you should perform 30% water changes once a week. If you have a small or crammed aquarium, bump that up to twice a week. Besides frequent water changes, you should clean the substrate regularly.

Get rid of any leftover foods that can stink up the aquarium. Adequate filtration is also crucial. Check your filter regularly and rinse out the filter media a few times per month. Use aquarium water to clean the filter. This way, you won’t be destroying the beneficial bacteria.

2. Monitor Water Parameters

Like all fish, Flowerhorns have an ideal set of water parameters. They’re also sensitive to fluctuations in temperature and pH.

Frequent changes in parameters can stress the fish. In the “best case” scenario, this halts growth and causes long-term health problems.

In the worst case, this can lead to shock and death. I recommend keeping the water pH as close to 7.0 as possible. This neutral pH is perfect for all fish and shouldn’t pose any problems.

Good filtration, plants, and frequent water changes will help you achieve this. The temperature should be between 80–85°F. For this, you’ll need a heater. It’s the best way to avoid temperature fluctuations.

3. Feed Them a Proper Diet

A well-fed fish is a happy fish. For Flowerhorns, the best diet is focused on protein-rich foods. High-quality flakes and pellets should be staples.

Foods like bloodworms, krill, and shrimp also help increase the hump size in Flowerhorns.

There are also specialized Flowerhorn feeds you can find online. Many people have reported nice growth with Humpy Head, Ever Red, and Grand Sumo.

4. Reduce Stress

Stressed Flowerhorns have smaller humps and paler colors. So, reducing stress levels might give your fish a kick start to develop better humps. This has mostly to do with bullying tankmates. Flowerhorns are aggressive and territorial.

Keeping multiple fish in the same tank is a recipe for injured and stressed fish. You might find your fish grow better when kept separate.

After all, the biggest hump is the mark of the dominant alpha. If there’s no competition for territory and resources, all fish get the same chance to reach their full potential.

5. Upgrade To a Larger Tank

A small tank might stunt your fish’s growth in multiple ways. Beyond increased stress, living in a shoebox is obviously bad for physical health.

Your Flowerhorns need room to swim, play, and get in their exercise.

You’ll find that your fish seems happier and more active in a larger tank. The extra energy expenditure will also increase their appetite, which is what you need to keep them growing.

The minimum tank size I’d recommend for this species is 70 gallons. The aquarium should also be at least 3 feet long, if possible.

6. DON’T Try the Mirror Trick

Many people swear by this method. Basically, you place a large mirror in front of the fish. When the fish sees its reflection, it perceives it as an enemy. This is supposed to promote territorial behavior.

This encourages the fish to grow larger, more colorful humps to assert dominance. It works in most cases.

But it also leads to long-term stress. Not something you want, as this can make your fish agitated and sick.


It seems like Flowerhorns grow big humps just for show. The kok doesn’t really do much other than store fat and fluid.

But it comes in handy during territorial displays between males. If your fish don’t grow a hump at all, don’t worry! The fish is perfectly healthy but might lack the necessary kok genes.

Sometimes, Flowerhorns might have small humps for reasons other than genes. Environment, nutrition, and stress also play a role in halting or enhancing the fish’s development.

If you follow the tips I’ve included in the article, you should see some improvement in the size and color of your Flowerhorn’s kok.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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