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Rainbow Shark 101 Care Guide for Beginners

Rainbow Shark 101 Care Guide for Beginners

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This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addition, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

Rainbow sharks are interesting freshwater fish that many people want to buy for their home aquariums. You might be thinking about buying some for your fish tank right now.

They could be good additions, but it’s important to learn about their needs before committing to buying them. You see, rainbow sharks are a little hard to care for overall.

Although rainbow fish can thrive in captivity, they have specific care requirements that some beginners might struggle with. You should learn about their needs so you can determine if buying these fish will be a good move or not in your situation.

These pretty fish can be a lot of fun to own. Once you know more about rainbow shark care, it’ll be easier to make the right call for your household.

Are Rainbow Sharks Hardy?

For the most part, rainbow sharks are considered to be hardy fish. They don’t necessarily die easily as long as they’re being kept in the right conditions.

Even though they’re considered to be a hardy species, they’re not recommended for beginners. This is because they can be a bit tough to care for when you don’t have experience caring for fish.

So you might wish to stick to other types of fish that are more beginner-friendly if you’re new to the hobby. Otherwise, it’s fine to buy rainbow sharks so long as you have a bit of experience.

If you’re new and you’re willing to learn how to approach rainbow shark care, it’s possible to do a bit of research. Below, you’ll learn about various aspects of rainbow shark care.

Knowing more about the care requirements will help you to avoid making mistakes. This should make it much simpler to have a good experience keeping these fish in your home aquarium.


When examining a rainbow shark’s behavior, you’ll find several interesting differences between wild rainbow sharks and captive ones. In the wild, rainbow sharks are much more passive and don’t seem to bully or bother other fish.

This changes when you put rainbow sharks in an aquarium. They suddenly become much more aggressive and have been known to become bullies.

Sometimes rainbow sharks will act aggressively in fish tanks. They might become territorial, and such issues will be more pronounced if you don’t keep the fish in large enough tanks.

It’s also notable that rainbow sharks are fairly active fish. Adult fish are known to swim around the bottom of the tank, and their most active time of day is the night.

Juvenile rainbow sharks are different because they’re timid and usually hide a lot. As the fish grow and age, they will become bolder and more aggressive.

It’s not unusual to see adult rainbow sharks biting and chasing other fish near the bottom of the tank. Sometimes they’ll even headbutt other fish or smack them with their tails.

The aggressive nature of these fish might be too much for many tank mates. So you need to choose tank mates appropriately if you plan to keep rainbow sharks in a community tank setting.

Natural Habitat

Rainbow sharks can be found living in many major rivers in Southeast Asia. The rivers where they’re most likely to be found are Chao Phraya, Mekong, and Xe Bangfai.

These fish like to hang out near the bottom of the river near the sandy substrate. They’re known to feed on algae and plankton to survive.

It’s normal for rainbow sharks to migrate to flooded areas seasonally. They then return to the rivers as the waters recede.

pH Level

Always make sure to keep an eye on the pH balance of the water. You want to make sure that it stays in the right range so the rainbow sharks will remain in good health.

The ideal pH balance range for rainbow sharks is between 6.5 and 7.5. You can use pH balance testing kits to test the water regularly.

If anything is a bit off, you can make adjustments using special chemicals. It should be easy to keep the pH balance in the right range so long as you’re using a filter and doing regular tank maintenance.

Keeping the water clean and safe for your fish is important. This is one thing you’ll always need to focus on when caring for any fish.


The temperature of the water matters quite a bit as well. Rainbow sharks won’t do well in tanks that are too hot or too cool.

They do best when the water temperature is kept between 72 degrees Fahrenheit and 79 degrees Fahrenheit. You can easily keep the water temperature in this range using a heater in the fish tank.

Monitor the temperature of the water by making sure that you have a visible thermometer on the tank. This allows you to see the temperature at a glance.

This is all very standard stuff, but it’s important to know if you’re new to caring for fish. You have to monitor the water parameters to keep your fish healthy.

Water Hardness

Rainbow sharks also have a preferred water hardness range. To keep things perfect for the rainbow sharks, you’ll want the water hardness to stay between 5 and 11 dGH.

Feeding Rainbow Sharks

Feeding rainbow sharks is another important aspect of care. You need to feed these fish the right types of food to keep them in good health.

These fish are omnivores, which means they eat both plants and meat. Wild rainbow sharks often feed on algae, but they’re also known to eat insects, larvae, and even some small crustaceans.

You’ll replicate this diet in the fish tank to an extent. You can feed the fish algae wafers as well as protein-rich foods such as insects.

Many rainbow shark owners choose to feed the fish brine shrimp and bloodworms. They also really enjoy eating veggies such as lettuce, zucchini, and peas.

It’s best to feed your rainbow sharks three times per day. Give them as much food as they can finish in five minutes and get rid of any extra food that they don’t eat so that it won’t negatively impact the water quality.

Tank Setup

Setting the tank up properly is of the utmost importance. Things can go badly when keeping rainbow sharks if you don’t give them the right tank setup.

The first thing to focus on is getting the right tank size. You want to put rainbow sharks in a 50-gallon fish tank or something larger.

Make sure that the tank is at least 48 inches long so that the fish will feel comfortable. When you want to put extra rainbow sharks in the tank, you’ll need to go even larger.

These fish are fairly active as adults, and they like swimming around the bottom of the tank. They need plenty of space so they can remain happy in captivity.

It’s also important to put the right substrate material in the tank. Mimic the natural habitat of the rainbow sharks and give them sandy substrate.

Putting various aquatic plants in the tank will be wise, too. This will help to keep aggression levels in check, and it will give them places to hide.

Some of the best plants for rainbow sharks include hornwort, java moss, and java ferns. You should also consider putting caves in the tank as well as other little hiding spots.

Do Rainbow Sharks Need an Air Pump?

You don’t need to buy an air pump for rainbow shark tanks as long as you have an appropriate filter. The filter should agitate the water enough to get oxygen into the water.

Some people do buy air bubblers for the tank, though. A bubbler to oxygenate the water can indeed be beneficial.

If you want to do things in the safest way possible, it’s best to buy a bubbler for the tank. This should help to keep your rainbow sharks in good health.

Do They Need a Filter?

Yes, it’s important to buy a filter for the tank. Without a filter, the water would get very dirty, and it also wouldn’t be good for oxygenation.

You should also know that rainbow sharks live in relatively fast-moving waters. Wild rainbow sharks are used to having water that flows a bit fast, and that means that you should mimic this with the filter.

Make sure that you buy a powerful enough filter for the tank that you choose. It will help to keep the water clean while also providing the appropriate water flow rate.

Generally, it’s always best to have a filter in the tank. You want to keep the water in good condition when caring for fish because things can get out of control when the water gets dirty.

Do They Need a Heater?

You absolutely need to install a heater in the tank for your rainbow sharks. These fish do best in water temperatures that range from 72 degrees Fahrenheit to 79 degrees Fahrenheit.

Without a heater, the water might get too cool for the fish. Also, fish don’t do well when the water temperature fluctuates wildly.

Fluctuating water temperatures can easily stress your fish and put them in a bad position. Stressed fish are more likely to get sick, and you don’t want your rainbow sharks to deal with such issues.

Getting a heater that can heat the tank properly is imperative. You can easily find a good heater that will help to maintain a consistent water temperature in the aquarium.

Do Rainbow Sharks Sleep?

Rainbow sharks are known to sleep sometimes. These fish are usually more active at night.

They like to sleep during the day and will utilize various hiding spots. It’s normal for them to hide in caves or find hiding spots near plants.

When they have more hiding spots, it helps them to feel safer when they sleep. You’ll notice the fish sleeping a lot during the day.

How Many Rainbow Sharks Should You Keep in a Tank?

It’s normal for people to keep just one rainbow shark in a tank. Rainbow sharks are kind of aggressive, and this can make keeping them in groups problematic.

You can keep rainbow sharks in groups, but you need a large tank. It’s best to have a 125-gallon fish tank or something larger when you plan to keep a small group of rainbow sharks.

Generally, it’s recommended to keep a group of at least five rainbow sharks if you plan to have more than one of them in a tank. This helps to keep issues with fighting from being too bad because the aggression will be spread out rather than just one or two fish getting bullied by the dominant rainbow shark.

You don’t need to keep multiple rainbow sharks in the tank if you don’t want to, though. Many people will have an easier time just keeping one rainbow shark in the aquarium.

It can be fun to keep a small group of rainbow sharks, but you need to be prepared first. Make sure you’re ready before you make the decision to proceed with buying a group of these fish.

Are Rainbow Sharks Community Fish?

Since rainbow sharks are somewhat aggressive, they’re not the best community fish in the world. This doesn’t mean that they can’t be kept in community aquariums, though.

You can put rainbow sharks in community tanks so long as they have enough room. Also, you need to choose appropriate tank mates for them.

Some fish are known to be good tank mates for rainbow sharks. These fish include various types of barbs as well as rainbowfish.

Usually, it’s fine to keep them with hardy fish that stay near the upper or middle portions of the tank. Many people have found success keeping rainbow sharks in tanks with gouramis, rasboras, certain types of loaches, and danios fish.

Some types of fish will get bullied by the rainbow sharks, though. It’s also important to put hiding spots in the tank to keep rainbow shark aggression levels in check.

How Long Do They Usually Live?

Most rainbow sharks will live between four and six years in a fish tank. It’s possible for the fish to live for as long as eight years when they receive excellent care, though.

If you do a stellar job keeping up with the care needs of these fish, it’ll be possible to enjoy them for a long time. They’re hardy enough that they’re not likely going to die easily, but they do need owners that take care of tank maintenance.

Your fish won’t do well if you don’t keep the tank clean or monitor the water parameters. So you need to be committed to keeping the fish safe.

This is why it’s not recommended for beginners to buy rainbow sharks. They need tank owners who will focus on regular tank maintenance and feeding the fish consistently.

Should You Purchase Rainbow Sharks?

The question of whether you should purchase rainbow sharks is one that only you can answer. Do you feel confident about buying these fish after reading all of the information above?

They’re somewhat aggressive fish that are usually kept alone. They can be kept in groups, but you’ll need a rather large tank if you want to do so.

Rainbow sharks are hardy fish, but they do require specific care. You need to keep the tank clean, focus on feeding the fish well, and monitor the water parameters closely.

Some fish owners won’t find it practical to keep these fish in their homes. They need large tanks, and they might be too aggressive for you.

However, many people love these fish and find them to be ideal. You might fall in love with how fun these fish are to observe in the tank.

Take all of the factors into account and then make the best decision for your household. If you choose to buy rainbow sharks, just be careful and remember to follow all of the advice that you received when setting up the tank.

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