Boxfish Care: Tank Setup, Diet, Tank Mates, Diseases & More!

Boxfish are fascinating creatures that can be a delightful addition to your saltwater aquarium. With their unique shape, vibrant colors, and intriguing behavior, they instantly become the center of attention in any marine environment.

Boxfish care involves providing a suitable aquarium environment, proper diet, and regular maintenance. These saltwater fish require a tank with plenty of hiding places and open swimming space. They need a varied diet of meaty and vegetable-based foods, including algae and seaweed. Regular water changes and maintenance are also important for their health and well-being.

I remember the first time I saw a boxfish in person; I was truly captivated by its distinct appearance. These fish can be demanding in terms of care, but I assure you, providing them with a suitable environment and proper nutrition will lead to a thriving and happy pet.

It’s essential to understand that boxfish require special attention and accommodation due to their sensitive nature. Adequate tank size, water quality, and compatible tank mates are crucial aspects to consider when taking on the responsibility of owning a boxfish. With the right information and preparations in place, you’ll be able to enjoy these vibrant underwater gems for years to come.

Boxfish 3

Species Summary


The Boxfish is a fascinating saltwater fish species originally found in the warm waters of the Indian and Pacific Oceans. It inhabits vast coral reefs with plenty of hiding spots. I remember my first time snorkeling in these areas, it was captivating to see them swimming among the corals.


A healthy Boxfish in captivity has an average lifespan of about 5-8 years with proper care and attention.


Boxfish 4

Boxfish are truly unique with their boxy, cube-like shape, due to their bony exoskeleton. They have vibrant colors, which often vary depending on the specific species.


Adult Boxfish typically range in size from 6 to 18 inches long, with the males generally being larger than the females.

Growth Rate

Growth in Boxfish can vary greatly depending on the specific species, but they are generally slow-growing fish. A juvenile can grow up to 1-2 inches per year.

Behavior & Temperament

Boxfish are known for their curious and peaceful demeanor. They are generally slow swimmers, which makes them quite endearing to observe. I’ve had a Boxfish approach me while diving, and it was a truly unforgettable experience.

Male Vs Female

Boxfish display sexual dimorphism, with males tending to be larger and boasting more vibrant colors than females in some species. This helps them impress and attract potential mates in their rich underwater environment.

Tank Setup

Tank Size

Boxfish require a large enough tank to swim comfortably. A minimum 30-gallon tank is a good starting point, as it allows adequate swimming space. I once made the mistake of starting out with a smaller tank and noticed the fish became stressed.


Appropriate lighting is crucial in creating an environment that mimics the natural habitat of boxfish. Using LED lights with a day-night cycle can make the fish feel at home.

Filtration & Aeration

It’s essential to have efficient filtration and aeration systems in the tank. Boxfish produce a lot of waste, which calls for a powerful filter. Make sure to have an air pump as well to maintain proper oxygen levels.

  • Filtration: Aim for a filter rated at least twice the tank’s capacity.
  • Aeration: Choose an air pump for a reliable flow of oxygen.


Maintain a stable water temperature between 72-78°F using an adjustable heater. A consistent environment makes it easier for boxfish to thrive and remain stress-free.


Boxfish prefer to dwell near the ocean floor, so it’s important to give them a comfortable substrate. A mix of crushed coral and marine sand creates a perfect environment for them to explore.


To replicate natural conditions, add various rock formations for boxfish to hide within. Providing hiding places is important to help these fish feel secure and at ease.


It’s a great idea to include live saltwater plants in the boxfish tank. They not only add a natural touch to the environment, but they also provide extra hiding spots and can help maintain water quality. Caulerpa and macroalgae are popular choices.

Water Quality

Water Temperature

Boxfish require a stable water temperature that ranges between 72-78°F (22-26°C). It is essential to maintain this temperature, as fluctuations can cause stress to the fish. I remember when I first started keeping boxfish, I didn’t pay enough attention to the water temperature, and my boxfish became very lethargic.

Water pH

Boxfish thrive in slightly alkaline water conditions. The ideal pH level is between 8.1-8.4. Regularly testing the water pH will ensure it remains within the appropriate range.

Water Hardness


These fish also need a specific water hardness, which means maintaining the dKH level between 8-12. This balance helps to create a healthy environment for your boxfish and allows them to remain stress-free.

Water Changes

Regular water changes are crucial for the wellbeing of your boxfish. I recommend changing 10-20% of the water weekly or 20-40% every 2 weeks. This helps to remove any waste buildup, maintaining the water quality for your fish.

Remember, proper water quality is essential in keeping your boxfish healthy and happy. Monitoring parameters like temperature, pH, and water hardness will ensure a thriving environment for these unique creatures.

Tank Maintenance

When I first started caring for my boxfish, I learned that maintaining a proper tank environment is crucial for their health and well-being.

To ensure your boxfish feels at home, maintain stable water parameters such as:

  • Temperature: 72-78°F (22-25°C)
  • pH: 8.1-8.4
  • Salinity: 1.020-1.025

Perform regular water changes (about 10-20% of the tank volume) every 1-2 weeks. This helps maintain water quality by removing excess nutrients and waste.

Filtration systems play a vital role in keeping the tank clean. Make sure to use a high-quality filtration system suitable for the size of your aquarium and replace filter media as needed.

Boxfish release toxins when stressed, which can affect water quality and harm tank mates. Regularly monitor your boxfish and ensure they have plenty of hiding spaces. Plants and decorations can provide these!

Keep an eye on algae growth within the tank. Algae can deplete oxygen and lead to poor water quality. Manual removal, algae eaters, or chemical treatments can help control it.

In my experience, maintaining a consistent and clean tank environment keeps my boxfish happy and healthy. Good luck with your tank maintenance journey!

Tank Mates

Compatible Fish Species

When considering tank mates for your boxfish, it’s important to choose compatible species. I once made the mistake of placing my boxfish with aggressive fish, and it led to unnecessary stress for both my boxfish and its tank mates. Here are a few species that typically get along well with boxfish:

  • Clownfish: These colorful, sociable fish are known for their peaceful nature and can be a great addition to a boxfish tank.
  • Goby: Gobies are small, bottom-dwelling fish that often coexist with boxfish without issues.
  • Tangs: Tangs, particularly the smaller species, are generally peaceful and can be compatible with boxfish.

Incompatible Fish Species

It’s crucial to avoid placing boxfish with fish that may not be compatible due to aggression or other factors. Here are a few species that may not make suitable tank mates for boxfish:

  • Lionfish: Recognized for their venomous spines, lionfish can pose a risk to boxfish and should not be housed together.
  • Triggers: These fish can be aggressive and territorial, which could cause stress and potential harm to your boxfish.
  • Eels: Although fascinating, eels can be aggressive and are not recommended as tank mates for boxfish.


What To Feed

Boxfish enjoy a varied diet, including both frozen and live foods. Feed them brine shrimp, krill, and bloodworms for a protein-rich meal. For vegetable matter, consider adding algae, seaweed, and spirulina.


I typically feed my boxfish twice a day, but some hobbyists feed them three times a day. It’s essential to find a balance that works for your fish to ensure they’re not overfed.


  • Observe your boxfish during feeding to ensure they’re eating well and not displaying signs of stress.
  • Remove any uneaten food to maintain water quality.
  • Adjust portion sizes if you notice your fish gaining too much weight.
  • Consider using a feeding dish to prevent the food from scattering in the tank, making it easier for your boxfish to find.
  • When I first introduced my boxfish to their new home, I offered live foods to help them acclimate and feel more comfortable.

Common Diseases


There are several diseases that commonly affect Boxfish. Some of these include:

  • Ichthyophthirius (commonly known as Ich)
  • Marine Velvet
  • Fin Rot
  • Bacterial Infections


As a Boxfish owner, it’s important to recognize the signs of illness. Here are some symptoms to look out for:

  • Ich: Small white spots on the body and fins
  • Marine Velvet: Gold or rust-colored patches on the skin
  • Fin Rot: Fraying or disintegrating fins
  • Bacterial Infections: Lethargy, loss of appetite, and skin lesions


When I noticed that my Boxfish was unwell, I took immediate action:

  • Ich: I used a copper-based medication and increased the water temperature by a couple of degrees.
  • Marine Velvet: A freshwater dip followed by formalin treatment significantly improved my Boxfish’s condition.
  • Fin Rot: I added an antibiotic to the water and watched closely for improvement.
  • Bacterial Infections: A broad-spectrum antibiotic can help combat various bacterial illnesses.


To minimize the risk of your Boxfish becoming ill:

  1. Maintain good water quality by conducting regular tests and water changes
  2. Quarantine new tankmates before introducing them to the main tank
  3. Keep a watchful eye on your Boxfish for signs of distress

Remember, an ounce of prevention is worth a pound of cure, and a happy Boxfish makes a happier you!

Signs Of A Healthy Boxfish

Boxfish 2

A healthy boxfish will exhibit vibrant colors and an active demeanor. They’ll have smooth, bony plate-like scales covering their body, with no visible injuries or parasites.

When observing the behavior of a healthy boxfish, you’ll notice they confidently explore their surroundings. In my experience, I’ve seen healthy boxfish swimming frequently, following tankmates, and nibbling on algae.

Proper nutrition plays a vital role in boxfish health. A well-nourished boxfish will have a plump body and clear eyes. Feeding them a varied diet of quality flake and pellet foods, supplemented with live or frozen seafood, can help maintain their vitality.

Key indicators of a healthy boxfish are:

  • Vibrant colors
  • Smooth scales
  • Active swimming
  • Clear eyes
  • Normal appetite

It’s important to monitor water parameters, as boxfish can be sensitive to changes in their environment. Ensure your tank maintains a stable pH, temperature, and nitrate levels to keep your fish thriving.

Signs Your Fish Is Sick

It can be challenging to notice subtle changes in your fish’s behavior or appearance. Here are some common signs that your boxfish may be feeling unwell.

  • Changes in color or appearance: A vibrant, healthy boxfish will have bright colors. If you notice dull, faded, or discolored patches on your fish, it may be a sign of illness.

Recently, I noticed my boxfish had developed some pale patches on its body. Upon closer inspection, I realized it was dealing with a mild bacterial infection.

  • Lethargy or unusual activity: Boxfish are usually active swimmers with a lively temperament. A sudden decrease in activity, hiding for extended periods, or erratic swimming patterns can indicate a health issue.
  • Loss of appetite: A decrease in appetite or refusal to eat food can be a sign of stress or illness. Monitor for changes in your fish’s eating habits.

Here is a table illustrating common signs of illness and potential causes:

Signs of IllnessPotential Causes
DiscolorationBacterial or fungal infections
Rapid breathingWater quality issues, parasites
Clamped finsStress, water quality problems
Swollen eyes or abdomenBacterial or parasitic infections

Remember, the key to keeping your boxfish healthy is prevention. Make sure you keep up with regular water changes, maintain water quality, and ensure proper nutrition. If you notice any signs of illness, consult a veterinarian or experienced aquarist for guidance.


Breeding Setup

To breed boxfish, I set up a separate tank with proper water conditions and hiding spots. I use a sponge filter for gentle water flow and maintain a stable temperature of around 77°F (25°C).

  • 20-gallon tank minimum
  • Plenty of hiding spots
  • Sponge filter
  • Stable temperature

How To Breed

Introducing a healthy pair of boxfish into the breeding tank is crucial. I usually feed them a high-quality, varied diet to encourage breeding behavior, including:

  • Brine shrimp
  • Mysis shrimp
  • Chopped seafood

Once the female lays her eggs, I remove the adults to prevent them from eating the eggs.


After the eggs hatch, I remove any unfertilized eggs. Remember that the larvae require tiny live foods such as rotifers or newly-hatched brine shrimp. Frequent water changes are also essential to maintain water quality. Keep the lighting low, as they’re sensitive to bright light during their early stages of life.

  • Rotifers or newly-hatched brine shrimp as food
  • Frequent water changes
  • Low lighting

One time, I raised a few boxfish fry successfully, which was a rewarding experience as they grew into fascinating adults. Patience and maintaining proper care are the keys to breeding these unique creatures.

Product recommendations for Boxfish:

  1. Hikari Marine S Pellets: This fish food is specially formulated for marine fish, including Boxfish, and provides a balanced diet for optimal health.
  2. Seachem Stability: This product helps to establish a healthy biological filter in your aquarium, which is important for maintaining good water quality for Boxfish.
  3. Fluval Sea Protein Skimmer: This protein skimmer helps to remove organic waste from your aquarium water, which can be harmful to Boxfish.
  4. Hydor Koralia Nano Aquarium Circulation Pump: This circulation pump helps to create a natural water flow in your aquarium, which is important for the well-being of Boxfish.
  5. Instant Ocean Sea Salt: This sea salt mix is perfect for creating a healthy marine environment for Boxfish and other saltwater fish.
  6. API Aquarium Salt: This product helps to promote healthy gill function and reduce stress in fish, including Boxfish.
  7. Seachem Prime: This water conditioner helps to detoxify ammonia, nitrite, and nitrate in aquarium water, which can be harmful to Boxfish.
  8. Coralife BioCube 16 Gallon LED Aquarium Kit: This aquarium kit is perfect for keeping Boxfish in a small space, and comes with a powerful filtration system.
  9. Koller Products AquaView 3-Gallon Aquarium Kit: This aquarium kit is perfect for beginners and includes a built-in LED light and filtration system.
  10. Marina Floating Thermometer: This thermometer helps you to monitor the temperature of your aquarium water, which is important for keeping Boxfish healthy.


In my experience, taking care of a boxfish has been a rewarding journey. These intriguing creatures, with their unique appearance, can be a wonderful addition to any aquarium.

To ensure their well-being, it is vital to provide ample space and appropriate water conditions. This includes a stable temperature and appropriate filtration.

Feeding a boxfish a varied diet is also necessary for their overall health. Include a mix of protein sources and vegetables to keep them satisfied and thriving.

Always remember to monitor your tank’s inhabitants for signs of stress or illness. Early intervention can make a world of difference when it comes to keeping your boxfish healthy and happy.

Don’t be afraid to consult with fellow enthusiasts or experts if you have questions or concerns about boxfish care. I found that engaging with others in the hobby proved to be invaluable as I learned the ins and outs of boxfish maintenance. Good luck on your boxfish journey!


Q: What do boxfish eat in captivity?

A: Boxfish are omnivores and eat a variety of foods, such as algae, small invertebrates, and meaty frozen foods. When I first got my boxfish, I had to experiment with different food options to find what my little friend enjoyed most.

Q: How big do boxfish get?

A: In general, they can grow up to 8 inches in size but the size may vary among species and genders. Regular monitoring of their growth is essential to maintain good health.

Q: What water conditions do boxfish need?

A: Ensure the water has a temperature of 72-78°F, a pH of 8.1-8.4, and salinity of 1.020-1.025 SG. Regular water changes and good filtration are essential as they’re sensitive to water quality.

Q: How can I make my aquarium suitable for a boxfish?

A: Provide plenty of hiding spots with rocks, caves, and live corals if possible. Ensure ample swimming space and avoid overcrowding so your boxfish can thrive.

Q: Are boxfish reef-safe?

A: While some species can do well in a reef aquarium, others may nibble on corals. It’s essential to research the specific boxfish species before introducing it to a reef tank.

Reference: Wikipedia.


Hi there! My name is Jacob, and I'm the founder of this Pet people blog that talks all about aquarium and fishkeeping. I've been passionate about fish and aquatic life since I was a kid, and I've spent countless hours learning about different species, their habitats, and how to create the perfect environment for them to thrive in.

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