How to Setup a Flowerhorn Tank?

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If this is your first flowerhorn, you need to prepare for a unique aquascaping experience. This species shares many similarities with other cichlids species, but it also showcases unique features that provide it with a colorful presence and distinct personality.

Choosing your favorite flowerhorn is merely the first step. Now you have to set up the tank, plan the layout, choose the right tank equipment, and acclimatize the fish to its new environment.

Today, I will teach you how to perform all these tasks perfectly to provide your flowerhorn with comfort and safety along the way.

So, let’s assess the most defining aspects of your flowerhorn’s environment:

Choosing a Tank for Flowerhorn

To jump in the middle of it, consider investing in a 70-gallon tank for one flowerhorn. These cichlids can grow up to 16 inches, with 10-12 being the average size.

They are also extremely territorial and inquisitive and will lap around their habitat constantly to secure and investigate it.

When it comes to providing flowerhorns with an adequate tank setup, here’s what you should consider:

  • A lot of horizontal space – Flowerhorns have no use for vertical space. Like most cichlids, flowerhorns swim horizontally and will rarely go to the water’s surface. Provide them with a long rather than tall tank, so they won’t feel claustrophobic and display signs of stress.
  • Minimal aquascaping – I advise against decorating your tank too heavily when talking about flowerhorns. These fish can get quite bulky and massive, as well as incredibly agile and energetic for a fish their size. Combine this with their Kok (the head nuchal hump specific in most males), and you can see why pointy, rugged, or large decorations might hurt the fish. Cuts, punctures, and scratches can quickly get infected, especially since flowerhorns are rather clunky with their massive and powerful bodies.
  • Leave room for the necessary tank equipment – You will need to use a heater and a filter which will take up room. Your flowerhorns require a lot of space, so make sure to invest in at least a 70-gallon tank for one fish to ensure enough room. The same goes for various necessary decorations like driftwood, rocks, and plants.

The tank’s size and overall setup will make a vital difference between a stressed and sick flowerhorn and a healthy, active, and strong one, perfectly accommodated in its environment. As a friendly reminder, you require around 150 gallons of water for 2 flowerhorns and around the same if you’re pairing the flowerhorn with other fish species.

Filtration for Flowerhorn

Without a reliable filtration system, you cannot create a safe, healthy, and stable environment for your flowerhorn.

The ideal filtration system should achieve 3 primary things:

  • Mechanical filtration – This refers to the filter media removing all floating particles that comprise dead organic matter, algae residues, food leftovers, and dirt. The filter media will trap all of the floating particles, keeping the water cleaner and clearer. How thorough the mechanical filtration will depend on the filter’s power and how fine the media is. I suggest testing several filter media to make sure you choose the one fitting for your aquarium.
  • Biological filtration – The filter’s media will house billions of beneficial microorganisms that feed on ammonia and nitrites and turn them into nitrates. The latter is far less harmful to fish, but you still need to dilute them via weekly water changes to prevent dangerous buildups. The filter’s bacterial film is necessary to any aquatic environment, cleaning your tank water and preventing the dangerous buildup of harmful chemicals. This feature is that much more important for cichlids, which are notorious for being messy and producing a lot of poop.
  • Chemical filtration – Chemical filtration relies on a carbon-based filter to remove any toxins and chemicals that your biological filter can’t handle. I recommend changing the carbon filter every 2 months or even sooner if your flowerhorn produces a lot of poop or you have multiple fish.

The filter’s power and the type of equipment you go for are essential as well. The golden standard is to have your filter’s flow rate adjusted to 5 to 10 times the tank’s capacity.

So, for a 70-gallon tank, you want a 700 gal/hour flow rate at most, which is quite a lot. This is necessary especially for flowerhorn and other cichlids, which are notoriously messy fish. Many people use 2 filters to cope with this power, which I also recommend.

This way, not only will you be combining the flowrate of 2 filters, but also benefit from different filtration media as well. That’s because not all filters deliver the 3 filtration methods I’ve described above.

That being said, what type of filter should you be using? I recommend investing in a canister filter for several reasons, mainly:

  • A lot of filter mediaCannister filters are generally large, capable of delivering a lot of power and holding a lot of filter media. They even allow you to use several types of filtering media depending on your needs. These are perfect for managing large volumes of water and ideal for a cichlid tank.
  • They don’t take up space – Cannister filters are mounted outside of the tank, so they won’t take any of your flowerhorns swimming space. This allows you more freedom in terms of aquascaping within the limits allowed by your flowerhorn.
  • More powerful – I would say that canister filters are the ideal choice for large aquariums like those meant for flowerhorns. In terms of power, canister filters offer the perfect results at a flow rate of 5 times the available water volume. For a 70-gallon tank, go for a flow rate of 350 gallons. Make sure you get the right filter capable of delivering this flow rate while remaining reasonably silent.

If I were to mention some cons, I would say that the canister filter is a bit more difficult to clean than other filters. Which is fine since you won’t need to clean it as often anyway; every 3-4 months should do.

They are also more expensive than other filters, but that’s also understandable given the many benefits they offer.

If you want to test other options, like HOB or power filters. Each has its own ups and downs, depending on what you need for your cichlid tank.

Whichever option you go for, make sure your filtering system achieves 3 things:

  • Doesn’t take up too much space in the tank; preferably not at all, which is why I opt for canister filters
  • Provides sufficient power to keep the environment fresh and stable
  • Ensures all 3 filtration methods, mechanical, biological, and chemical

Heating for Flowerhorn

Flowerhorns definitely need a tank heater due to them preferring higher water temperatures. The flowerhorn will remain comfortable at temperatures around 78 to 85 F, which is high even for tropical fish.

There’s little-to-no chance that you can maintain these temperatures stable without a heater.

And the problem is that even seemingly benign temperature fluctuations can cause your cichlid to experience health problems. So, you need to use a heater powerful enough to heat up the tank water uniformly and maintain it at the desired value with minimal intervention from your part.

There are multiple tank heaters available, each coming with various features and at different prices.

No matter the piece you’re choosing, I recommend the following as standard must-haves:

  • Different wattage options – I suggest choosing a heater that presents several wattage options, from 50 W to 300, 500, or even more, depending on your tank’s size. This is especially recommended if you plan on increasing your tank size with time. At least you won’t have to buy a more powerful heater.
  • Protection – Heaters lacking protection could end up hurting your fish. This is especially likely with fish like flowerhorns that tend to be extremely active and inquisitive. Go for a heater with a protective grid to save your fish from accidental burns.
  • Ease of temperature adjustment – Avoid heaters that only allow you to change the temperature manually by removing them from the water. Choose one that allows you to adjust the temperature values externally, preferable even remotely.
  • Hardiness and material quality – Always read the product’s reviews before purchasing it. The heater needs to comprise quality material that will withstand the test of time and water attrition.

As a side note, I recommend getting 2 heaters for a 70-gallon tank. Generally speaking, you need 300 W of power for a 70-gallon tank, but the surface area is too large. Your heater won’t be able to heat up the water uniformly, no matter how powerful it is.

I recommend getting 2 300-watt pieces and placing them on opposite sides of the tank for maximum effect.

Substrate for Flowerhorn

To understand which type of substrate to use for your flowerhorns, you need to understand your flowerhorns first. These are aggressive, active, and very inquisitive fish, constantly roaming around their environment, sticking their nose wherever they can.

As is typical with cichlids, the flowerhorn will play with its substrate a lot, looking for food and digging around in the process.

Knowing this, I believe sand is the best choice for your flowerhorn and cichlids in general for several reasons:

  • It mimics the cichlids’ natural environment – The thing is, flowerhorns don’t have a natural environment since they’re the result of selective breeding. So, they don’t exist in the wild. That being said, they do share the cichlids’ genetically-defined preferences, which includes their substrate-related behavior. They, too, will dig around the substrate for food and even when playing, and sand is great for that.
  • It protects them – Sand is fine-grained and doesn’t risk hurting your fish. Unlike other substrates like river rocks or gravel.
  • Easy to clean – Sand comprises fine particles sticking together to form an almost impenetrable mass. This means that all the fish waste and food residues won’t sink in as easily, making it easier for you to vacuum and clean it.

Sand comes in a variety of colors in case you’re interested in different esthetic looks, but I recommend darker options for a nicer contrast. Your flowerhorns will love it too.

Decoration for Flowerhorn

The main problem here is that flowerhorns are overtly inquisitive fish that like to dig into the substrate, bump into things, and investigate every element placed in their habitat.

Knowing this, choosing the right plants and tank decorations can be quite challenging.

When it comes to choosing the best aquarium decorations for your flowerhorn tank, here’s what to avoid:

  • Extremely large pieces – Don’t use large rocks, driftwood, or decorative elements that take up too much space. Flowerhorns require a lot of open space for swimming, so keep the decorations smaller.
  • Dangerous elements – Here, we include decorations with pointy or rugged surfaces, as well as those with toxic paints. These can affect your fish’s health in the long run, leading to cuts, body lesions, or high toxicity levels that could kill the flowerhorn.
  • Inadequate structures – Knowing your flowerhorn’s tendencies to push, bump into, and dig beneath everything, using large or dangerous structures as tank decorations is a bad idea. The flowerhorn may tip them over, wreaking havoc around their habitat and even sustaining injuries in the process. Keep the decorative elements heavy, smooth, and compact, making them difficult to move or tip over.

Knowing all this, I recommend using rocks and some driftwood for your flowerhorn tank. Not too big, not too small, but robust enough to prevent the flowerhorn from moving them too easily.

When it comes to plants, few are capable of withstanding the flowerhorn’s cichlid-specific plant-destructive behavior. Java fern and anubias species make for decent choices in this sense.

Cycle the Tank First

Cycling the tank before introducing your flowerhorn into the environment is a must to prevent the risk of sudden death via ammonia poisoning. The procedure is easy in theory, but it will last around 6 to 8 weeks to complete, depending on the tank’s size.

You shouldn’t skip the cycling process despite this inconvenience since it would be a death sentence for your flowerhorn.

To simplify the process, here are the necessary steps that the cycling process consists of:

  • Get a water tester kit to monitor the process and acquire valuable data along the way
  • Fill the tank with water and add pure ammonia until the ammonia level in the tank reaches approximately 4 ppm
  • If the ammonia level surpasses 5 ppm, you need to perform a partial water change to dilute the chemical
  • Mount the filter and the heater to provide the nitrifying bacteria with the ideal conditions to grow and multiply. The temperature should remain around 65-85 F, while the filter will control the ammonia levels and oxygenate the water
  • Two to three weeks into the process should begin to produce nitrites; this is a sign that the cycling process is going according to plan
  • The nitrite levels shouldn’t exceed 5 ppm; if they do, you need to perform a partial water change, usually replacing around 30% of the water
  • It will take an additional two, three weeks for the nitrates to show up
  • When they do, measure the water parameters, add more ammonia to reach 4 ppm, and allow the process to continue for 24-48 more days
  • This should be enough time for the nitrites and ammonia to fall to 0, while nitrates should remain below 20; this is the sign that the cycling process is complete
  • It’s now safe to add the flowerhorn

Remember always to perform the cycling process before getting the fish. This way, you won’t have to keep the fish isolated in an unfit environment for 8 weeks until the cycle process completes.

Flowerhorn Tank Mates

You should be very careful when adding any additional fish to your flowerhorn tank. These fish are extremely aggressive and territorial and will often fight relentlessly for their food, space, and sometimes out of pure cichlid aggression.

If you insist on building a more vivacious community with several fish, I recommend the following:

  • Keep a pair of flowerhorn like pretty much everyone else

Yea, there’s only one reliable option. You could also pair your flowerhorn with other fish like big cichlid species, Oscars, plecos, or the spotted hoplo catfish, but problems are always guaranteed.

Cichlids are mostly aggressive, and the only thing that keeps them in check is the presence of other cichlids. Preferably a lot of them. The more cichlids there are in the environment, the calmer they tend to get.

Unfortunately, you can’t afford the luxury of a cichlid-fill fish tank since flowerhorns require a lot of space for themselves. They don’t do well in overcrowded environments, causing them to snap and become extremely violent towards any tank mate invading their space.

So, for safety reasons, only pair flowerhorns with other flowerhorns. And make sure you provide each fish with sufficient space to prevent aggression.


Flowerhorns are fascinating cichlids that can be very rewarding when cared for, loved, and maintained properly.

They don’t need much, so long as you provide them with the basics:

  • Enough space to roam around freely
  • A sandy substrate to cater to their digging needs
  • A healthy and stable environment with optimal living conditions
  • Stable temperatures
  • A nutritious and diverse meal plan

Other than that, flowerhorns are just like any other cichlid. Plus, the 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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