Arowana Care Sheet

Arowana Species Overview

The arowana is a prehistoric, slender freshwater fish found in the tropical waters of South America, Asia, Australia, and Africa. In some cultures, certain species of arowana are thought to be symbols of health, good luck, and prosperity. This care sheet outlines basic care needs for a variety of arowana species, including: 

• Silver arowana

• Jardini arowana 

Due to their large size and reputation as aggressive fish, arowanas are best suited for hobbyists with experience keeping fish. Since arowanas are more sensitive to nitrates than other types of fish, pet parents need to perform regular partial water changes and test their aquarium’s water quality often to ensure the tank’s nitrite level is close to zero. 

Arowanas can grow up to two inches per month during their first year. In adulthood, they can reach lengths of three feet or more! Arowanas use their long, whisker-like barbels near the bottom of their mouths to sense movement on the water’s surface. 

Arowana Characteristics 

Difficulty of Care	Intermediate to advanced, depending on species
Average Lifespan	10 to 20+ years with proper care
Average Adult Size	3+ feet, depending on species
Diet	Carnivorous
Minimum Habitat Size	150+ gallons, depending on species
Water Temperature	72–82 F
pH	6.0–7.0

 

Arowana Supply Checklist

To keep an arowana happy and healthy, pet parents should have these basic supplies on hand: 

• Appropriately sized aquarium  

• Appropriate food, dry and frozen  

• Décor  

• Water conditioner  

• Filter  

• Water test kit  

• Full-spectrum lighting  

• Hood  

• Net  

• Thermometer  

• Freshwater substrate    

• Heater   

• Airline tubing  

• Air stone  

• Air pump  

• Check valve  

• Freshwater salt  

• Refractometer or hydrometer 

Arowana Habitat

Choosing the Right Enclosure 

Arowanas need an aquarium that’s at least 150 gallons to accommodate their long bodies and fins. Since arowanas tend to swim near the top of their tank’s water, the aquarium’s length and width measurements are more important than its height. Ideally, the tank should be long and wide, with a large bottom surface area (or “footprint”) so the arowana has enough space to swim and turn comfortably in the water. Always provide the largest habitat possible for any pet habitat. 

Arowanas are known to be powerful jumpers, especially if startled, so their tank should be secured with a fitted aquarium hood to prevent the fish from injuring itself. An arowana's tank should be kept in a quiet area of the home, away from direct sunlight, windows, or air conditioners. 

Setting Up Your Habitat 

Selecting Tankmates 

Adult arowanas are solitary fish and it’s recommended to keep them separate from other fish. Keeping more than one adult arowana in the same habitat can encourage stress, aggression, and competition. 

If another fish is kept in the same habitat as an adult arowana, the fish must be large so the arowana can’t swallow them whole, and they should be a “bottom-dwelling” fish (like large catfish species and plecos) that won’t occupy the upper-section of the tank, where an arowana will build its territory. 

Filtration 

A filter system is an essential addition to any aquatic habitat. Aside from keeping tanks looking clean, filters remove harmful toxins like ammonia from the aquarium's water and add oxygen to the water so fish can breathe. An aquarium’s filter should be powerful enough to process all the water in the tank at least four times an hour. For example, a 150-gallon tank (minimum recommended size for an arowana) should ideally have an aquarium filter with a flow rate that’s at least 600 gallons per hour (GPH). If only a 550 or 700 GPH filter is available, purchase the 700 GPH option.  

Power filters (also known as “hang-on-back" filters) and external canister filters are recommended because they offer effective mechanical, biological, and chemical filtration and do not take up as much space.  

Recommended Products: 

• Eheim Classic 600 External Aquarium Canister Filter, 159-gal 

• Penn-Plax Cascade Aquarium Canister Filter, 200-gall 

• Marineland Multi-Stage C-530 Aquarium Canister Filter, 150-gal       

The water in an arowana’s tank should have a moderate to strong circulation to mimic the water currents and high oxygen levels found in their natural habitat. An appropriately sized air stone, air pump, and airline tubing can be added to the tank to improve water movement and add oxygen to the environment, making it easier for fish to breathe. 

Recommended Products: 

• Tetra Whisper Air Pump for Deep Water Aquariums  

Water Health & Salt Content  

An aquarium’s water should be tested regularly to ensure its pH, ammonia, nitrate, and nitrite levels are stable and within a safe range. An aquarium test kit, like the API 5 in 1 Freshwater & Saltwater Aquarium Test Strips, should be used to measure key water parameters quickly and accurately. 

Adding freshwater aquarium salt to an arowana’s tank can help support the fish’s gill health. If freshwater salt is added to the aquarium, the water’s specific gravity should be kept at 1.004 and should not change more than +/- 0.001 in 24 hours. A hydrometer or refractometer (salt level tester) should be used to measure the salt concentration and specific gravity of the aquarium’s water. 

Recommended Products: 

• Freshwater Aquarium Salt 

• API Freshwater Aquarium Salt 

• Refractometers/Hydrometers 

• D-D H2 Ocean Salinity Refractometer 

• Instant Ocean Testing Hydrometer for Aquariums  

Temperature 

Arowanas are tropical fish that thrive in water temperatures between 72–82 degrees F. An aquatic heater should be installed in the tank to ensure that water temperatures stay within an ideal range and do not fluctuate more than +/- 2 degrees F in a single day. Heaters should be paired with a thermostat to regulate the aquarium’s temperature and prevent the water from rising above the ideal range. Many modern heaters have built-in thermostats. 

The wattage needed for the aquarium heater depends on the enclosure’s size and the ambient temperature of the room where the tank is kept. As a rule of thumb, aquarium heaters should have between 2.5–5 watts of power for every gallon of water in a tank. This means that a 150-gallon tank needs a 375- to 750-watt heater. Pet parents can place two 300-watt heaters on opposite sides of their 150-gallon tank to prevent cold spots from developing. 

Recommended Products: 

• Eheim Jager Thermostat Aquarium Heater, 300-watt 

• Eheim Thermocontrol E Fish Aquarium Heater, 300 W 

Pet parents must check the water temperature of their arowana’s tank daily using an aquarium thermometer. 

Recommended Products: 

• Marina Floating Thermometer with Suction Cup for Aquariums 

• HDE LCD Digital Aquarium Thermometer 

Tank Décor & Accessories 

Plants and driftwood: Although arowanas will spend most of their time near the surface of their tank, pet parents can still decorate and create hiding places by adding driftwood and ornamental plants to their aquarium.

Arowanas are large fish that need plenty of swimming space, so make sure their aquarium isn’t too crowded. Submerged plants should be well-secured in the tank’s substrate to prevent them from topping over and injuring the fish. All décor should be rinsed thoroughly before being added to the tank. 

Recommended Products: 

• SubstrateSource Cholla Wood Aquarium & Terrarium Driftwood 

• Underwater Treasures Cardamine Fish Plant 

• Underwater Treasures Green Jungle Vallisneria Fish Plant 

Cleaning & Maintenance for Arowana Fish Tanks

Pet parents can maintain the condition of their arowana’s tank by performing routine water changes (no more than 10-25% of the aquarium’s total water volume) every 2–4 weeks. Draining and replacing the aquarium's entire water volume should be avoided, as doing so will remove the beneficial bacteria that keeps the habitat’s ecosystem healthy.  

Most fish tanks will need a full cleaning once a month, depending on the number of fish in the tank. To fully clean a fish tank, take these steps: 

1. Before cleaning or performing any maintenance on an aquarium, hands should be rinsed and washed thoroughly, ensuring that they don’t have any trace residue of lotions, perfumes, or other toxic chemicals that can harm fish. Do not remove the fish from the aquarium because it will stress them out and possibly injure them. 

2. Use a soft sponge or scrubber to scrape the inside walls of the aquarium. To prevent unsightly scrapes and scratches, acrylic tanks should only be cleaned with specialized cleaning tools designed for acrylic aquariums, such as the API Extra Long Algae Scraper for Acrylic Aquariums or API Algae Pad for Acrylic Aquariums. 

3. Remove the aquarium’s accessories and any artificial plants that have significant algae growth. Use an algae pad and hot water to scrub any build-up or debris.  

4. If the décor is still visibly dirty after being scrubbed, use a 3% bleach solution to remove the stubborn build-up. Accessories should soak in the diluted bleach solution for 15 minutes before being rinsed thoroughly with running water until there are no residual smells from the bleach. After cleaning, leave the accessories to air-dry fully. 

5. Inspect the aquarium’s filter to ensure it’s working properly and doesn’t have any algae buildup. If the filter needs to be cleaned, follow the manufacturer's instructions. 

6. Use a siphon vacuum to remove waste or old food from the bottom of the tank. This step will also drain water from the tank and prepare the aquarium for a water change. 

7. Once the aquarium’s gravel is vacuumed, check the cleaned décor to ensure all furnishings are fully dried and do not have a bleachy smell before adding them back to the tank. 

8. Add new, dechlorinated water to the tank to replace the water that was siphoned out. The new water must be detoxified with a water conditioner to remove toxic chemicals like chlorine, chloramines, and heavy metals. The added water should be at the same temperature as the existing water in the tank. 

9. Use an aquarium-safe cleaner to clean the outer walls of the aquarium. Household cleaners should be avoided, as they often have ammonia and other chemicals that are toxic to fish. 

Arowana Diet & Nutrition

Arowanas should be fed floating pellets or sticks designed for surface-feeding, carnivorous fish, as well as live, frozen, or freeze-dried fish, insects, krill, worms, and shrimp.  

Young arowanas should be fed 2–3 times a day, while adults can be fed once daily. At each feeding session, the fish should be able to consume all the food added to its tank within 1–2 minutes. 

A nutritious and well-balanced diet for an arowana consists of: 

Floating pellets or sticks designed for surface-dwelling, carnivorous fish

Recommended Products: 

• NorthFin Arowana Formula 3 mm Floating Sticks Fish Food 

Live, frozen, or freeze-dried fish, insects, worms, and shrimp 

Young arowanas should not be given insects and invertebrates with sharp or very hard shells. Frozen foods must be thawed before feeding. 

Recommended Products: 

• Tetra JumboKrill Freeze-Dried Shrimp Freshwater & Saltwater Fish Treats 

• San Francisco Bay Brand Freeze-Dried Krill Fish Food 

• Tetra BloodWorms Freeze-Dried Fish Food 

Considerations for Pet Parents

Before turning on aquarium lighting in their arowana’s tank, pet parents should turn on any ambient lighting in the room where the aquarium is kept. Otherwise, the arowana might get startled and try to jump out of their tank. 

Before being added to an aquarium, water must be treated with a water conditioner to remove toxic chemicals like chlorine, chloramines, and heavy metals, and the added water should be at the same temperature as the existing water in the tank. 

Recommended Products:  

• API Tap Water Conditioner 

• API 5 in 1 Freshwater & Saltwater Aquarium Test Strips 

An aquarium’s filter, water temperature, and other equipment should be checked daily to ensure that they’re working properly. Filter media should be replaced monthly or rinsed in old tank water during water changes, depending on the water condition and the number of fish in the tank.  

Arowanas are more sensitive to nitrates than other fish species, so pet parents need to perform regular partial water changes and test their aquarium’s water quality often to ensure the tank’s nitrite level is as close to zero as possible. 

Arowana Veterinary Care

Annual Care

In a properly maintained tank of appropriate size, it is okay to only utilize a veterinarian if there is a problem with your arowana. Almost all arowanas will likely have at least one health issue so it is recommended to have your fish and your setup assessed by a veterinarian within a week of establishing them at your home. It is recommended to find an aquatics veterinarian who can make house-calls, as transport is a major stress event for fish and adult arowanas are typically too large for transport.

Signs of a Healthy Arowana

• Clear eyes

• Full range of motion of fin movement

• Intact fins all the way to the edges with no discoloration

• Regular and active swim pattern

• Large appetite

• Swims at the top of the water column

When to Call a Vet

• Changes to the arowana’s coloration—particularly becoming dull, focal spots of change, stripes or bands of color change

• Lethargic swimming potentially with an abnormal pattern such as circling, listing to the side, staying on the bottom of the tank, etc.

• Receding fin edges with or without discoloration at the edges

• Decreased appetite for more than a day

• Itching

• Rapid breathing potentially with flared gills

• Gill color changes

• Presence of lumps/bumps/masses

• White growths/spots of any kind

• Cloudy or bulging eye(s)

• Elevated scales

• Weight loss

• Bloating

Common Illnesses in Arowanas

• Fin/tail rot

• Dropsy (fluid filled coelomic cavity)

• Parasites

• Bacterial infections

• Cancer

• Ich

• Pop Eye

• Fungal oral or skin infections

• Swim bladder disorders