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Chili Rasbora: An Ultimate Care Guide

Chili Rasbora: An Ultimate Care Guide

Is something missing from your aquarium? A chili rasbora might be the perfect addition if you’re looking for a nano fish. These fish are relatively easy to take care of and make fantastic pets. 

Chili rasbora requires a dark substrate aquarium and less food than your average aquarium fish because of their tiny size. Though little, they need specific and attentive care. Like all fish, they need food, attention, veterinary support, and stimulation.

Before adopting a chili rasbora, it’s important to understand how to care for them correctly. This article will explain everything you need to know about caring for a chili rasbora. Let’s get started! 

Chili Rasbora Species Overview

The chili rasbora (also known as Boraras brigittae) is a freshwater fish that is a part of the Cyprinidae family. This popular tank fish has very distinctive and delicate features and is bright red in color. 

With the proper care, this fish species is fantastic for beginners. 

Here’s a video of this beautiful fish:

The chili rasbora originates from Indonesia and is often found in habitats with many mosquitos, giving them a second name of mosquito rasbora. In the wild, they live in blackwater streams and sometimes swamps and are known for being very mild-natured, which makes them great community fish.  

Chili Rasbora Size, Appearance, and Lifespan

Chili rasbora is a nano fish variety that is incredibly tiny and can fit into smaller tanks. The biggest they grow to is ¾ of an inch (19.05 mm) long, which is minute compared to other aquarium fish. Although they’re small, chili rasboras are easy to spot because of their beautiful red color.

Male chili rasbora fish have striking, fiery red coloring, while females are duller. They also have a noticeable thick black band across the body and bright red spots on the fins. Chili rasbora fish are slender with large round eyes. 

Although chili rasboras are small, they have a long lifespan. They typically live between 4 and 8 years but can live longer if you care for them well. Although their lifespan is shorter than that of other aquarium fish, it’s a good lifespan for such a tiny fish. 

Chili Rasbora Temperament

Chili rasbora fish are active and peaceful fish and tend to swim and explore the entire tank. As long as they’re paired with other peaceful fish, there shouldn’t be an issue with aggression. You should avoid more aggressive fish, which can threaten a chili rasbora and cause their color to fade. 

Chili rasbora may seem lethargic or lazy if you don’t provide them with enough stimulation. Under normal circumstances, they are active, swim around happily, and will be peaceful with their fellow tank mates. 

If your rasbora behaves outside of this norm, they may have an underlying physical illness, which I’ll address later. 

Ideal Tank Conditions for a Chili Rasbora

Chili rasboras are low-maintenance fish, but it’s still important to understand what helps them to thrive in the tank. Your chili rasbora may become ill if it doesn’t have suitable tank conditions, and setting your tank up to be a safe environment will benefit you and your chili rasbora in the long run. 

If you don’t have an established tank, you should allow at least 24 hours for its temperature, pH, and composition to settle before introducing your chili rasbora. 

Water Temperature and PH

The ideal tank temperature for a chili rasbora is between 68-82°F (16.66-27.77°C), as they are tropical fish. Though they can be forgiving to some water changes, you should avoid anything colder or warmer as it can stress the fish. If you have an existing tank community, ensure the water temperature is compatible so every fish can feel comfortable. 

The water pH is important for a chili rasbora. The water is a bit more acidic in their natural habitat due to the chemicals released from decaying plants in the environment. The range is wider than most and is from 4.0 to 7.0. However, you should aim for 6.0, which is the sweet spot for this species.

Ideal Tank Size

Since chili rasbora are nano fish, they can be accommodated in tanks as small as 5 gallons (about 19 liters). This makes them ideal for fish enthusiasts who don’t have a lot of space in their homes to accommodate a large tank. 

However, you should use a nano tank only if you have no more than 2 chili rasbora. If you have other fish, you’ll need a larger aquarium. 

A 10-gallon tank (about 20 liters) is ideal for a chili rasbora and a few other fish species. 

It’s important to remember that a bigger tank isn’t necessarily always better. Of course, a larger tank is much better than a too-small tank but be prepared for the added work of a larger tank because it can be more difficult maintaining the correct pH and temperature in a larger one. 

Tank Maintenance 

In the wild, chili rasbora fish live in environments with very few minerals. If you plan to use tap water in your tank, use a water conditioner to soften it and remove the excess minerals. Distilled water is also an excellent solution. 

You should also perform regular and partial water changes and have a good filtration system in your tank to keep your chili rasbora healthy and happy.  

Ideal Habitat for Chili Rasbora

As active fish, chili rasbora love swimming around the tank and need enough space to do so. 

By carefully curating the substrate, plants, and decorations, your chili rasbora will be thankful for your efforts. 


A dark substrate is best for your chili rasbora, as it replicates its darker habitat in blackwater streams. Fine gravel or sand is suitable for chili rasbora as long as it’s not too bright. They’re used to dark, decayed leaves in their environment, and leaving a darker substrate will mimic this effect. 


Plants also greatly benefit your chili rasbora, as they’re used to being around many plants in their natural environment. You should consider floating and rooted plants so your fish have enough to explore and diffuse some of the tank light. Some excellent plant options for your chili rasbora include: 

The more plants you can provide for your chili rasbora, the better. Although the above plants are highly recommended for this species, they do well with most aquatic vegetation.


Chili rasbora is small, and a strong current in your tank can make it difficult for them to swim. Having many plants in the tank can help prevent this. Consider adding heavy decorations, such as driftwood and logs, to break up the current. 

Make sure that whatever you add to your tank is suitable for aquatic settings. Tank decorations that aren’t compatible with water can damage your tank. In some cases, they can throw off the pH, introduce harmful chemicals, or cause mold to develop in the tank and on your fish. 

What To Feed Your Chili Rasbora 

Chili rasboras like eating insects, worms, and larvae. Feeding them a mixture of foods is great for their overall health as long as the pieces are small enough for them to ingest. Suitable food sources for a chili rasbora include: 

  • Brine shrimp
  • Daphnia
  • Fish flakes or pellets
  • Micro worms
  • Bloodworms

Whatever you feed them, remember this is a small fish species that doesn’t need too much food. Overfeeding your chili rasbora can make them sick and cause the tank to become dirty much quicker due to the leftover scraps. 

Most aquatic shops can provide you with food for your chili rasbora, but using online resources could help if your rasbora doesn’t like the generic food you feed them. I suggest a diet of dry fish flakes and a few extras (such as those listed above) to enrich their diet. 

When feeding your chili rasbora dry flakes, you’ll need to crush them in a mortar and pestle to form a powder, as the flakes are too large for them to eat. 

However, if you include brine shrimp, micro worms, or blood worms, follow the correct storage protocols. 

Ideal Tankmates for a Chili Rasbora

Chili rasbora is also a schooling fish, so make sure you have a minimum of 6 individuals at all times. Being in a large school can make a chili rasbora happier in its tank, and large schools are also more exciting to watch. This means that, unlike beta fish, you should avoid only having one chili rasbora at a time. 

If you’re considering adopting a chili rasbora, try and adopt at least a handful of fish. 

Additional tank mates can enrich your chili rasbora’s life and create a diverse aquarium. If you’re new to having an aquarium and have only had beta fish in the past (who can’t be in a tank with another fish), then learning that chili rasbora need friends around might be surprising.

Chili rasboras do best with other peaceful fish. Due to their small size, avoid larger fish that may see them as prey. Although chili rasbora are peaceful fish, other fish varieties can be more aggressive, and you should try and introduce other laidback species. If not, they’ll bully and possibly eat your little chili rasbora. 

It’s best to keep chili rasbora fish with other small fish that won’t threaten them. Luckily, chili rasbora’s beautiful color is a showstopper, so you don’t need many tankmates to make the community interesting.

The best tank mates for chili rasbora include: 

Each of these fish species makes a great companion for a chili rasbora school. Though the fish might not interact, they’ll live in the tank harmoniously. 

If you already have chili rasbora in your aquarium but are keen to adopt an aggressive fish species, please place them in separate tanks. 

Breeding Your Chili Rasbora

Chili rasbora can easily be bred at home in the tank with the right conditions. They are egg scatterers, so if you plan to breed, you should get a separate breeding tank so the babies can grow and survive without other fish trying to harm them. You can tell your chili rasbora are ready to breed when the male fish becomes brighter and starts to chase the female around the tank. 

When you observe breeding behavior, move the fish to a breeding tank. The tank parameters should match the main tank, and if you want to successfully harvest the eggs, you should also have an egg crate to avoid the fish eating their eggs. Move the parents back into the main tank as soon as you see eggs. 

The eggs hatch within 1 to 3 days and can go 24 hours before you start feeding them. For their safety, allow them to grow a little before introducing them to the main tank. 

Taking Care of Chili Rasbora Newborn Fish

Newborn fish, more commonly referred to as fry, aren’t too complicated to take care of, the most important thing to remember is that fish parents aren’t always kind. 

Sometimes, especially with chili rasbora, the parents may try to attack the babies or eat them. This is why it’s recommended to have a separate breeding tank.

Otherwise, take care of the newborn fish like your regular chili rasbora. Ensure their tank is acclimated to their needs, give them plenty of food, and keep an eye out for any irregular behavior. 

Can You Crossbreed Chili Rasbora?

Though it may feel like a fun and exciting idea to crossbreed your chili rasbora with another rasbora, it’s generally not advisable. Crossbreeding chili rasbora with other fish species is difficult and sometimes impossible and heightens the chances of eggs not hatching. 

However, you could do some selective genetic breeding. Suppose you’ve noticed that some of your rasboras have more desirable traits, such as swimming speed or coloring. In that case, you can continue to breed this rasbora to create a generation with these traits. Here’s an example of what that might look like.

Though this video is about betta fish, the concepts are true for other fish breeding, including that of the chili rasbora. 

Breeding your fish for fun or sale is only ethical if you care for them and provide them with suitable tank conditions and enough food. 

Acclimating Your Chili Rasbora To The Tank

Keep a close eye on your chili rasbora after releasing them to monitor potential odd behavior. Though properly acclimating them can feel like a lot of work, introducing them too quickly is detrimental for their health. They’ll likely fall ill or die if this is done incorrectly. 

This is relevant for new fish in your breeding tank becoming acclimated to the main tank or fish in general when placing them in the main tank. Various things can affect the success of a transfer. 

Some of these include:

  • Lighting
  • Temperature
  • pH
  • Water composition

Make sure you’re adding your new fish to the main tank with the lights low, the temperature just right, and the pH at the desired level. 

How To Keep Your Chili Rasbora Healthy

To keep your rasbora healthy, ensure that you maintain optimal tank conditions. This means cleaning your tank periodically, only adding the right types and chemical compositions of water, and consistently monitoring the pH.

You should also be wary of adding new fish and ensure the fish you adopt come from reputable sources. Unfortunately, some pet stores don’t care for their fish as aquarium enthusiasts do, and you may purchase a fish that already has an illness or parasite. 

You may want to quarantine any new fish in a quarantine tank for a week or two before adding it to the main tank. This way, you can monitor it for any symptoms of ich or ulcers and prevent infecting your other fish. It’ll also give you time to treat the fish and acclimate it to the main tank. 

Signs of Illness or Stress in a Chili Rasbora

Now that you know how to take care of your chili rasbora, it’s important to know what signs to look for to ensure they’re thriving in their new tank. Introducing them to the tank should be a slow and meticulous process to ensure they don’t get sick or die from shock. After that, you should monitor them for signs of illness. 

Like other fish, chili rasbora can become sick despite our best efforts to keep them safe. Tanks that are overcrowded or kept in poor conditions can make them sick. However, they can still get sick even when you do everything you can. Some signs of illness or stress in your chili rasbora include: 

  • Red ulcers
  • Bloating
  • Popped eye
  • White spots (ich)
  • Faded color
  • Lesions
  • Scratching on rocks or decor
  • Grey spots 
  • Erratic Swimming 
  • Lethargy

If you notice any symptoms on this list, various conditions may be the cause, and consulting a vet or expert is advisable. Since chili rasbora are schooling fish, you should treat the issue before it spreads to the other fish. 

Red Ulcers

Red ulcers are also called epizootic ulcerative syndrome. It can be caused by fungus in the tank and looks like it sounds–big red spots or ulcers affecting your fish.

To avoid red ulcers, ensure your tank is clean, and there is no mold present. Everything inside of your tank should be suitable for an aquarium. Otherwise, they can gather mold. 

The top of your tank is also susceptible to mold, so pay attention to the space between the water, the filter, and the top of the tank. Mold can grow here and trickle down into your tank, causing red ulcers on your fish. 


Water belly, dropsy, or “bloating” are all prevalent in fish populations. You’ll notice your fish’s belly looking large, swollen, and almost like they’re bloated or full. This can happen simply by feeding your fish too much or due to a bacterial infection or parasite. 

Dropsy can be cured with antibiotics and strict monitoring. 

Popped Eye

Popped eye or “Popeye” disease in fish causes large and swollen eyes resembling those of the cartoon character Popeye. 

This can be caused by injury, infection, or even poor water conditions. If you notice this, it’s likely an infection or poor water conditions. However, it could be an injury if it affects only one of your fish. 


White spot disease, or ich, is another common fish illness. You’ll notice white spots on the fish in your tank.

Ich is more serious than the above illnesses because it’s caused by a parasite. You’ll likely need to hospitalize or quarantine the affected fish by adding them to a new tank and treat the parasitic infection appropriately. 

What To Do if Your Chili Rasbora Is Sick

The first thing you should do if you’re worried your chili rasbora is sick is determine the cause. You may be surprised to learn that you can take your fish to the vet. If your tank is too large to transport, you can take your chili rasbora to the vet in a plastic bag filled with tank water. 

There are also aquatic experts and aquarium enthusiasts who could assist you. 

Once you have a diagnosis, order the necessary treatments. You should also separate your chili rasbora from its tankmates to prevent the disease from spreading if it’s contagious. 

Give your fish a few weeks in an isolation tank to let it recover before adding it back into the tank. 

Chili Rasbora FAQs

How many Chili Rasbora should be kept together?

Chili Rasboras should be kept in schools of 6 or more. If you do have a larger school, you’ll notice more interesting behavior.

Are Chili Rasboras hard to keep?

Chili Rasboras are relatively easy to take care of, however, it is important to understand what helps them thrive. Make sure you maintain good water quality and provide a suitable environment for them to flourish.

How big do Chili Rasboras get?

The biggest they grow to is ¾ of an inch (19.05 mm) long. They may be little in size but they’re big in color!

Can Chili Rasboras live with Neon Tetras?

Yes, they can, but because Chili Rasboras are smaller than Neon Tetras you’ll need to make sure Neons aren’t outcompeting them for food.

Are Chili Rasboras good for beginners?

Chili Raboras may not be an ideal fish if you’re a beginner. Even though they are low-maintenance, they do need to be kept in a well-established and properly maintained aquarium.

Wrapping Up

If you’re looking for a new fish to add to your tank, a chili rasbora will add color and liveliness without needing too much space. Just be sure that this fish is compatible with your tank’s other fish because they’re tiny fish that can easily become prey for larger and more aggressive fish. 

Chili rasbora makes for an easy aquarium population if you’re interested in one fish and one fish only. Breeding rasbora isn’t too complicated, and the colors are dazzling.

I’m Elle, the founder of FishHQ. I created this website to share knowledge, tips, and inspiration for beginner hobbyists to help them create a healthy, happy, and vibrant environment for their fish to thrive. Read more...