Can Flowerhorn and Pleco Live Together?

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If you know anything about flowerhorns, you know they are unique, gorgeous, and aggressive cichlids that don’t get along with pretty much any other fish species. The ideal tank mate would preferably not get in the flowerhorn’s way and keep a low profile.

This brings us to the bristlenose pleco, the famous catfish playing the role of a tank scavenger better than any other species.

Pairing the flowerhorn with any tank mate will come with specific logistics problems for a variety of reasons.

These include:

  • The flowerhorn’s aggression causes them to display extreme territorial behavior and attack any fish entering their space
  • The need for high temperatures that many fish species aren’t accustomed to (78-85 °F)
  • The flowerhorn’s inquisitive nature and high levels of energy cause them to roam their environment 24/7
  • Their appetite for destruction led them to dig around the substrate, unearth plants, and even move and tip over heavier tank decorations, and so on

Most people will pair flowerhorns with other flowerhorns, preferably in compatible pairs, since males cannot stand each other in the same habitat. When it comes to pairing the flowerhorn with other fish species, nothing is set in stone.

There are some recommendations, but you should always take them with a grain of salt.

In this context, are plecos the right fit? Let’s have a look.

Are Plecos Compatible with Flowerhorn?

Yes, they are, up to a point. The main selling point here is that plecos are bottom-dwellers, so they won’t interact with the flowerhorn as often.

They like to remain in hiding, for the most part, feeding on algae and organic matter around the substrate. That being said, flowerhorns will often patrol the substrate and play around, digging and looking for food.

Flowerhorns aren’t bottom feeders, but rather opportunistic ones, looking for a quick meal wherever they might find it. This could bring them in direct competition with the plecos, but nothing you can’t handle. They will only temporarily invade the pleco’s territory, and the latter will avoid confrontation anyway.

As we will see, there are ways to accommodate both species, provided you consider some strategies along the way. So, let’s dive right into those!

How to Keep Pleco with Flowerhorn?

We should consider several areas when aiming to accommodate plecos and flowerhorns in the same environment.

These include:


Flowerhorns are omnivorous, and they thrive on a bit more protein in their diet compared to other fish species. They are cichlids, after all. Typically, around 40% of the flowerhorn’s diet should consist of animal protein from sources like shrimp, fish, bloodworms, daphnia, pellets, and even feeder fish.

The one thing you should remember about flowerhorns is that they are extremely voracious in typical cichlid fashion. Their digestive system is also rather sensitive and ineffective, which is also characteristic of cichlids.

These two facts suggest that it’s extremely easy to overfeed flowerhorns which will cause them a variety of health problems, constipation being one of them. Overfeeding will also pollute their environment, and cichlids are sensitive to fluctuations in water parameters.

So, flowerhorns require a carefully-planned meal schedule with enough food that they can consume within 3-4 minutes. Don’t rely on their appetite to inform you when they’re full because they rarely are.

Bristlenose plecos have different dietary and feeding behaviors. These catfish are almost exclusively herbivorous and will mostly feed on stuff they can find on the substrate. This includes algae, detritus, and other plant and animal-based expired matter.

As bottom feeders, their feeding behavior will contribute to keeping the tank cleaner, preventing algae bloom, and contributing to a more hygienic environment.

That being said, you shouldn’t rely on them achieving their nutritional requirements from their environment alone. I suggest feeding them a balanced diet once or twice per day, consisting of various products to ensure proper nutritional intake.

These include spirulina wafers, algae supplements, granules, sinking pellets, and even homemade veggies and bloodworms.

Don’t attempt to feed your plecos any floating flakes since they won’t swim to the water’s surface to collect them.

Space Requirements

Flowerhorns require a lot of space since they are extremely territorial and active, swimming around their habitat relentlessly.

A fully-grown flowerhorn requires at least 70 gallons of water, especially since these cichlids can grow quite large, typically more than 10-12 inches. You should double the space available for each flowerhorn you introduce to the environment.

Bristlenose plecos, on the other hand, are not as demanding. They will do just fine with only 20 gallons per fish, especially since plecos don’t typically grow more than 5 inches.

The pleco will have the time of its life in a 70-gallon tank, provided you ensure the optimal aquarium layout. Coincidentally, this is exactly what we will be discussing next.

Tank Layout

Every fish species has certain requirements when it comes to its tank layout. Some require plants, others need a variety of hiding spots, while some will do fine in bare environments.

The flowerhorn leans more towards the latter, primarily because of its aggressive, active, and curious nature. The flowerhorn will investigate, bump into, and poke at anything in their tank, be it decoration, rock, plant, driftwood, or any other element.

This makes aquascaping close to useless in their case.

Bristlenose plecos, on the other hand, rest at almost the opposite part of the spectrum. They thrive in heavily planted aquariums, preferably with a variety of hiding spots and driftwood decorating the substrate.

They need caves, tunnels, driftwood, and rocks to hide when stressed, which tends to happen when sharing the same space with a 12-inch-long aggressive cichlid.

The same structures will provide the pleco with food since all tank decorations, especially driftwood, will house algae, detritus, and other organic matter that plecos will enjoy.

As you can see, the two species aren’t exactly compatible in this area, but I think you can make it work.

Here are some useful recommendations to take with you:

  • Use heavier decorative rocks, but not big enough to deprive the flowerhorn of its valuable swimming space
  • Avoid large decorative elements for the same reason and for the fact that flowerhorns can tip them over
  • Avoid decorative elements with sharp and rugged edges that could hurt both your flowerhorn and pleco
  • Always place the rocks directly onto the tank bed and sprinkle the substrate around them. This will provide them with more stability, preventing the plecos or the flowerhorn from digging beneath them
  • Provide your pleco with plenty of hiding spots that aren’t too large but are heavy enough to withstand the flowerhorn’s inquisitive spirit
  • I would say avoid live plants because the flowerhorn will destroy or eat them anyway
  • Make sure the pleco has a lot of driftwood around for a constant source of food

These measures should accommodate both the flowerhorn and the pleco, minimizing the interactions and aggression between the two.


Flowerhorns are aggressive and territorial but will mostly guard the middle section of the tank. And will display more aggression towards fish that get into their face constantly, which doesn’t usually happen with the plecos.

That being said, the two will stumble across each other, as flowerhorns tend to spend a lot of time near the substrate.

This isn’t necessarily a problem, so long as your pleco has a lot of hiding places to retreat to. Plecos are generally peaceful, but they might get irritated when other fish invade their territory.

Provided they have any way of intimidating the intruder, which isn’t likely to happen with a flowerhorn, given that the cichlid can overgrow the pleco 3 times over. Plecos will save their most aggressive behavior towards other plecos for the most part.

Water Requirements

Both flowerhorns and plecos prefer similar water conditions. Flowerhorns are more comfortable in temperatures around 78 to 85 F, while plecos prefer to remain in the range of 73 to 81 F.

This means that you can overlap their preferences easily to accommodate both species in the long run.

Regarding other water parameters, flowerhorns and plecos aren’t that different either. They need stable water conditions with 0 ammonia and nitrites and 2 to 20 dGH water hardness.

The only noticeable difference is in the water pH, since plecos sit at 5.8 to 7.8, while flowerhorns prefer values between 7.0 and 8.0. So, there’s some wiggle room in there as well.

Can Flowerhorn Eat a Bristlenose Pleco?

It’s unlikely for that to happen. Flowerhorns will eat smaller fish, but adult plecos aren’t that small. They are too large for the flowerhorns to swallow whole, and they don’t exactly fit the cichlid’s meal plan.

That being said, cichlids are opportunistic predators, and the flowerhorn is no exception. They will undoubtedly kill and eat plecos that are too small, especially as fry when they cannot defend themselves.

To prevent that, I recommend 2 useful strategies:

  1. Introduce the pleco first – Place the pleco in the aquarium first, preferably while still a juvenile, to allow it to accommodate within its environment. The flowerhorn should come later, once the pleco has figured out its habitat’s layout and is comfortable and secure.
  2. Ensure an optimal layout – Plecos require a well-designed hiding system, preferably consisting of caves and tunnels. This helps them take refuge whenever faced with an immediate threat which can often happen when in the presence of a flowerhorn. Make sure the decorative elements are heavy and robust enough to prevent the flowerhorn from breaking, budging, or tipping them over.


Flowerhorns aren’t exactly the most welcoming fish species, so they won’t get along with too many tank mates. Plecos, however, can work, provided you understand each species’ requirements, and you accommodate both of them.

Generally speaking, your flowerhorns won’t interact much with your plecos because they prefer different dwelling areas.

Even so, I suggest always keeping an eye on their interactions. If it gets too steamy in there and you can’t cool off their relationship, consider separating them to avoid a potentially imminent tragedy.

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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