How to Care for Madagascar Rainbowfish?

Disclosure: I may earn a commission when you purchase through my affiliate links. As an Amazon Associate I earn from qualifying purchases. – read more

Photo by Guérin Nicolas CC BY-SA 3.0

The Rainbowfish is a highly adaptable, peaceful, and vibrant tank fish that enjoys the company of other aquatic creatures. These are several of the reasons why Rainbowfish are so beloved in the aquatic business.

The fish’s variation is another important factor since there are more than 50 species of Rainbowfish available.

Today, we will discuss the Madagascar Rainbowfish, aiming to shed light on one of the most beautiful and docile tank fish you can find.

Madagascar Rainbowfish Requirements

While the Madagascar Rainbowfish isn’t too pretentious about its habitat’s layout and water parameters, it still has certain requirements to address.

The most important ones include:

Tank Size

The Madagascar Rainbowfish can reach a size of up to 6 inches, so it requires at least 30 gallons of space. Most aquarists rely on a 50-gallon tank since it allows them to accommodate the fish better.

The Rainbowfish is a peaceful creature, so it’s unlikely that will ever display territorial aggressiveness when overcrowded or kept in a small setting.

Instead, it will experience stress which will affect its health long-term. It’s also worth noting that Madagascar Rainbowfish are active and fast creatures that love to patrol their habitat.

They will spend their lives in the tank’s middle and top area with only occasional dives to the bottom.

It’s safe to say that they require significant space to feel comfortable and remain active and at peace.

Water Parameters

The Madagascar Rainbowfish requires relatively stable water parameters with temperatures between 72 and 78 F.

There is room for some variation, but not too much since temperature fluctuations can hurt the Rainbowfish. The pH should remain between 6.5 and 8.5, which is quite a generous range.

When it comes to overall water quality, Rainbowfish demand regular cleaning and maintenance, as well as optimal filtration. These are standard requirements for all fish species since few of them can live in dirty waters. And those that do survive but won’t thrive, will display shorter lifespans and poorer overall quality of life.

Unlike other tank fish, Rainbowfish demand some water flow as well. Keep it moderate, and watch how your fish react to it.

Some Madagascar Rainbowfish may need steeper currents since it helps them breathe better and remain more active.

Just make sure that the water currents won’t damage the tank’s layout like various decorations and plants. Or disturb other fish in case you’re running a community setup.


The Madagascar Rainbowfish doesn’t mind any type of substrate since this is a mid-to-top dweller.

However, it appears that they prefer a darker substrate since it mimics their natural habitat better.

When it comes to the type of aquarium substrate to use, it all comes down to personal preference. It’s important to remember that different substrates have different pros and cons.

In this sense, we have:

  • Sand – Sand looks great, comes in various colors, and imbues your tank with a natural look. It’s also a good option if you’re after a heavily planted aquarium that your Rainbowfish will appreciate. Sand is also good because it prevents fish waste and food residues from sinking in. The particles are too small, and there’s too little space between them. So, all the waste will remain on top, allowing you to clean it easier. The main downside is that, when stirred by fish, it can fill the water with floating particles which can clog the filter.
  • Gravel – Gravel looks amazing, is cheap, and works better for planted tanks. It also comes in several sizes, colors, and shapes and doesn’t go hard on the filtration system. There are, of course, several problems to mention, one of which is the fact that fish can eat it by mistake. Ingesting gravel particles by mistake can clog their digestive system and even kill them. This substrate is also more difficult to clean since all the waste will pass through the gravel rocks and bury itself beneath the substrate. They will rot there, increasing the ammonia levels and poisoning the tank.
  • River rocks – These are a good option for Madagascar Rainbowfish, especially since they have little interest in spending too much time near the substrate. So, the river rocks will mostly benefit the tank’s aesthetics. And any occasional algae grazers you might decide to add to the tank later on. Just make sure you avoid rocks containing too much calcium since these can alter the water’s pH and chemistry. Avoid crushed coral, marble, limestone, or geodes in favor of granite, lava rock, slate, quartz, or sandstone.

Ultimately, when choosing your tank’s substrate, always consider the possibility that you may transform your tank into a community setup at some point.

So, be mindful of what other fish species may need in terms of the substrate. Your Rainbowfish will be fine either way.


Rainbowfish won’t typically hurt plants, despite being omnivorous fish. They prefer getting their nutrients from flakes and pellets and whatever else you might feed them.

So, feel free to experiment with different aquarium plants to see which fit your Rainbowfish environment the best.

Some Rainbowfish will occasionally nip at some plants, especially if they’re hungry or not getting enough plant-based nutrients.

Some will even eat live plants as a hobby, no matter how well you feed them. Unfortunately, it’s unlikely that you’ll be able to tell which Rainbowfish will eat plants beforehand.

I recommend java moss and java fern as the most popular options, but you can also choose Anubias, crypts, hornwort, Amazon swords, etc.

As a hint, if your Madagascar Rainbowfish enjoys eating live plants, there’s nothing you can do about it.

No matter the amount of veggies or spirulina you’ll provide them with, they will continue to eat plants.


A reliable filtration system is a standard requirement for Rainbowfish, as well as most tank fish. The same goes for the heater, despite Rainbowfish not requiring high water temperatures.

The role of the heater is to keep water temperatures stable and prevent dangerous fluctuations that could stress the fish.

Managing the filtration system, in particular, is important since Rainbowfish need moderate water currents to thrive.

The water flow may sometimes interfere with the rest of the aquatic setting, whether it’s plants, decorations, or other fish.

In general, most aquarists rely on redundant filtration when housing Rainbowfish in larger tanks in excess of 75 gallons.

Redundant filtration refers to using 2 filters instead of one, which can provide several benefits, including:

  • Ensure balanced water flow without the need of boosting one filter’s power output
  • Ensure a well-rounded filtration effect (chemical, biological, and mechanical)
  • Provide additional support in tanks that are too large for only one filter

Madagascar Rainbowfish Feeding and Diet

The Rainbowfish needs a diverse and nutritious diet to thrive. Fortunately, the fish is easy to satisfy since it can consume a variety of fish foods.

They can accommodate to pellets and flakes fairly easily, but they also require live prey occasionally. This will help them preserve their natural hunting behavior, which is quite prevalent among wild Rainbowfish.

In the wild, these fish consume a variety of insects, most of which they catch on the water’s surface. Feeding them live insects may be trickier, but you can provide them with some live food occasionally to satisfy their appetite.

These fish require proper protein intake to remain healthy and retain their vivid colors in the long run.

Bloodworms, brine shrimp, water fleas, tubifex worms, algae wafers, and veggies are all good and nutritious food sources for them.

You may also feed them supplements 2-3 times per week which is often necessary to optimize their growth, preserve their coloring, and keep them in good health.

Make sure you rather feed Rainbowfish 2-3 times per day in smaller portions, rather than providing them with one larger meal.

Madagascar Rainbowfish Tank Mates

Fortunately, the Madagascar Rainbowfish is a peaceful and docile fish that will rarely, if ever, display any territorial or aggressive behavior.

When looking for compatible tank mates for your Rainbowfish, consider the following:

  • The size difference – If the Rainbowfish’s tank mates are too large, they might bully or even eat the Rainbowfish. If they are too small, things might turn the other way around. While Rainbowfish doesn’t typically exhibit predatorial behavior, it will, however, operate under the same rules governing the fish world. In other words, the Rainbowfish can eat smaller fish if the size difference between them is significant.
  • The fish’s behavior – Avoid aggressive fish species. Madagascar Rainbowfish only feel comfortable in the company of docile, friendly, and peaceful species. Aggressive and territorial fish like cichlids will make the Rainbowfish uncomfortable and subject it to bullying over time. In these conditions, the Rainbowfish will look to hide rather than fight, and its life quality will drop as a result.
  • The fish’s temperament – I know this sounds like a word game since ‘temperament’ and ‘behavior’ are often used interchangeably, but it’s not. The temperament refers to the fish’s general demeanor. Some fish are more active and energetic, while others are lazier and more sluggish. Rainbowfish are among the former, and you should pair them with similarly-tempered fish, primarily because Rainbowfish do everything in a hurry, including eating. Slower eaters may starve when housed with the more energetic and vivacious Rainbowfish.
  • The numbers – Too many fish in one place can lead to territorial violence even among more peaceful species. Rainbowfish like to have their space to swim and mind their own business without having to bump into other fish constantly. If you’re going for a community setup, make sure the tank is large enough to accommodate all species.
  • The male-to-female ratio – Madagascar Rainbowfish are schooling fish, which means they need to be kept in groups of at least 6 individuals. The problem is that Rainbowfish males can become quite territorial and aggressive towards one another. Especially if they have to compete over females. The sexual instinct is the most well-developed natural drive in all creatures, heavily influencing their behavior and relationships. Rainbowfish are no different. To mitigate sexual-fueled violence, always have 2-3 females for every Rainbowfish male. Such a ratio will diminish the need for male violence since there will be enough females for everybody.

Typically speaking, Madagascar Rainbowfish are peaceful and docile fish that will get along with most tank fish. Make sure their future tank mates are also peaceful, and they will all get along just fine.

Some good options include dwarf cichlids, barbs, tetra, danios, peaceful bottom-dwellers like plecos, etc.

As an important note, pay attention to the dynamics between Rainbowfish and infamous fin nippers like Neon Tetras. These small and inquisitive fish will harass fish with larger fins and pursue them throughout the tank. If that happens, you may wish to remove the bullies to prevent your Rainbowfish from becoming stressed.

Don’t be fooled by the tetras’ seemingly innocuous appearance. These fish can be relentless when they set their eyes on a pair of colorful and flappy fins.

Madagascar Rainbowfish Diseases and Treatments

The Rainbowfish doesn’t show any specific genetic predisposition toward any disease. They will face the same fish conditions that plague all species, mainly Ich, swim bladder disease, fin rot, and other parasitic or bacterial infections.

Like with any disease, prevention takes priority over treatment, and early treatment takes priority over late-stage treatment.

But what can you do to keep your Rainbowfish in good condition and keep it safe from parasites and bacteria?

Consider the following:

  • Mind the fish’s genetic makeup – This boils down to where you’re getting your fish from. Most fish shops keep their fish in foul conditions and won’t be bothered by concepts like water changes or tank maintenance. Or breeding tanks, for that matter. This will result in Rainbowfish engaging in interbreeding and producing genetically subpar offspring. These fish will experience a shorter lifespan and possible physical deformities and display an increased sensitivity to parasites and diseases. Get your fish from reputable sources, preferably experienced breeders with a reputation in the field.
  • Ensure optimal water quality – All tank fish need adequate water quality to remain healthy and happy in the long run. While the filtration system helps, it’s not enough to preserve the system’s stability and prevent ammonia buildup. You should also perform regular water changes, remove fish waste and food residues, and occasionally clean algae deposits and dirt. You should also clean the filters since they may clog at times.
  • Provide a balanced diet – Rainbowfish require a stable and diverse diet to remain healthy. Unfortunately, many aquarists forget these aspects and only offer their fish flakes or pellets. The lack of food variation will cause the fish to experience nutrient deficiencies that will drop their immune system as a result. Some may even result in health conditions related to various vitamin or mineral deficiencies.
  • Mind the water temperature – Something as innocuous as the water temperature has the potential to kill your fish. We’re not talking about drastic fluctuations in temperature, which will send your fish into thermic shock. No, it’s nothing as severe. Instead, we’re referring to repeated minor temperature fluctuations that will cause your fish discomfort along the way. This will affect your fish’s immune system with time, making it vulnerable to parasites and bacterial infections as a direct consequence. Rainbowfish require stable temperatures with as little variation as possible.
  • Avoid stress – This shouldn’t be too difficult since Rainbowfish are pretty positive, energetic, and lively fish. There aren’t too many things that will stress them out, but some will. We include here drastic or repeated fluctuations in water conditions (temperature, pH, hardiness, overall quality), aggressive tank mates, insufficient food, overstocking, or insufficient swimming space. Stressed fish will soon experience weaker immune systems, which we have already determined leaves them vulnerable to various diseases.
  • Source the fish’s food carefully – This problem is prevalent in the aquarium business, especially among more inexperienced aquarists. Many people feed their fish wild-caught insects or worms, not realizing the dangers they’re carrying. These insects are often filled with parasites or come from heavily polluted areas, which means that their tissues are stocked with dangerous chemicals. Both are bad news for your Madagascar Rainbowfish for obvious reasons. Always get your fish’s food from trustworthy sources, or you can even grow it yourself. Homemade veggie paste and home-bred live food are safe, healthy, and nutritious food options if you have the time and commitment for it.

Naturally, these prevention methods aren’t failproof. Sometimes, your fish will get sick, at which point early treatment is necessary to contain the disease. When ignored, most fish disorders prove fatal in later phases, even if they’re otherwise easy to manage.

Fortunately, all fish will display clear symptoms, allowing you to pinpoint the condition and figure out the best treatment approach early on. Watch for signs like lethargy, refusal to eat, irritability, swimming and buoyancy problems, discoloration, skin and fin lesions, etc.

If your Rainbowfish displays any of these symptoms, ensure a targeted treatment in a hospital tank. I consider quarantining the fish to be the smartest move in this context.

Quarantining the sick fish will:

  • Prevent the parasites from multiplying in the main tank
  • Prevent the parasites from infecting other fish
  • Protect the fish’s environment in case you need to use antibiotics or medication that could affect the tank’s biofilm
  • Allow greater control over the sick fish’s setting and improve the treatment’s effectiveness

When it comes to the treatment itself, consider adding salt to the fish’s tank to counter the parasites.

This is generally one of the preferred methods of treatment since it boosts the fish’s natural healing capabilities and promotes healthier mucus production. Antibiotics may also be necessary in case of infections, either primary or secondary.

Aside from that, your fish will require pristine water conditions and a nutritious diet to strengthen its body. Your Rainbowfish requires daily water changes during the treatment.

So long as you’re tackling the disease in its primary phases and providing optimal care, your fish should recover fairly fast. Keep the Rainbowfish in quarantine for at least 2 weeks to make sure everything is on the right path.

If your fish doesn’t show any signs of recovery, you should consider euthanasia to end its suffering.

How Big do Madagascar Rainbowfish Get?

A fully-grown, healthy Madagascar Rainbowfish can reach 6 inches. However, most will remain smaller than that, in the neighborhood of 4 inches.

A variety of factors influence the fish’s size and growth rate. These include available space, nutrition, feeding schedule, tank mates, and overall quality of life.

The fish’s genetic makeup is also of paramount importance. If your fish is genetically faulty, all your efforts of boosting its size and growth rate will prove useless.

So, always source your Rainbowfish from reputed sources, as we’ve already discussed.

How Long do Madagascar Rainbowfish Live?

The Madagascar Rainbowfish can live between 5 to 11-12 years, depending on a variety of factors.

These include:

  • Genetic makeup – If your Rainbowfish comes from parents with short lifespans, the offspring may follow the same route. That is, no matter what you do to change the outcome. The good thing is that it’s unlikely that you will know how much the fish’s parents have lived. So, you will have to provide your fish with the optimal care and hope for the best.
  • Water conditions – Rainbowfish demand stable and optimal water conditions to thrive. Sure, they can survive in suboptimal conditions, but they will lose years of their lives with time. Invest in a peak filtering system, clean and vacuum the fish’s habitat regularly, and perform water changes whenever necessary.
  • Stable feeding schedule and a diverse diet – Many aquarists will feed their fish regularly during the first few months, then gradually loosen up as years go on. They may skip some meals here and there, forget the importance of food variety, and even sacrifice food quality at times. All these issues will visibly impact the fish’s health and lifespan over the years.
  • Avoid fish stress – Rainbowfish can get stressed for a variety of reasons, as I’ve already explained. These include poor water conditions, inadequate diet or feeding pattern, aggressive tank mates, parasites, etc. The more stressed they are, the lower their lifespan over time. The constant stress will also leave them vulnerable to diseases due to their immune system becoming less effective with time.
  • Keep them in groups – Madagascar Rainbowfish have a pretty well-developed social instinct. They like to socialize and enjoy the company of other fellows Rainbowfish, which helps them become calmer and more confident in themselves. Just make sure there are enough Rainbowfish females to go around. Otherwise, the males may begin to step on each other’s fish toes.

The Rainbowfish doesn’t need much to thrive. Stick to the basics, provide it with optimal care, and your fish will flourish.

Are Madagascar Rainbowfish Aggressive?

No, Madagascar Rainbowfish are almost never aggressive. The only things that could stir them up would be reproductive and food competition.

Otherwise, the fish are not territorial and will tolerate any other fish species so long as their tank mates are friendly and calm.

Are Madagascar Rainbowfish Good for Beginners?

Absolute, they are. Rainbowfish are fairly easy to care for, pretty much along the lines of any other popular fish species. They have basic needs and are not pretentious at all about their diets and environmental layout.

You should be able to care for the fish with relative ease, so long as you consider its fundamental needs.


The Madagascar Rainbowfish makes for a fine addition to any aquatic setup.

Choose its tank mates carefully, provide optimal care, and your Rainbowfish won’t ask for anything else.

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.
Leave a Comment

Your email address will not be published. Required fields are marked *