Arowanas: Water Pollution Or Natural Habitat?

Arowanas are a species of fish that are part of the ancient family of osteoglossidae. They are also known as bony tongues due to a toothed plate of bone on the lower part of their mouth. Native to the inland waters of Southeast Asia, these fish are highly prized in Asian cultures as symbols of good luck and prosperity. Their resemblance to the Chinese dragon has made them popular for aquariums. However, their popularity has contributed to their status as an endangered species. Arowanas are known for their large size and aggressive feeding habits, and they require proper filtration and maintenance to prevent water pollution and ensure optimal water quality.

Arowanas produce large amounts of waste

Arowanas are large, carnivorous fish that produce a lot of waste. They are highly predatory and require a high-protein diet to support their rapid growth and satisfy their big appetites. This means that their waste can easily pollute the water in a tank if an efficient filtration system is not in place.

Arowanas are part of the ancient family of osteoglossidae, which are sometimes called "bony tongues" due to the toothed plate of bone on the lower part of their mouth. They are native to the inland waters of South America, Southeast Asia, and Australia, and can grow up to 90 cm (35 inches) long. Their large size means that a 150-gallon aquarium is the minimum size recommended to keep them healthy.

As they are highly adapted to fresh water, arowanas require a well-filtered, soft, and slightly acidic water environment, with a temperature of 24-30°C (75-86°F) or 72-82°F, depending on the source. The water should be changed regularly, with no more than 10-25% of the total volume of water changed every 2-4 weeks, and a full cleaning of the tank should be performed once a month.

Arowanas are sensitive to water quality and are more sensitive to nitrites than other fish. They require a powerful filtration system that can process all the water in the tank at least four times an hour to maintain optimal water quality and prevent pollution. Recirculating aquaculture systems (RAS) and bioremediation are two possible technologies that can be used to minimize pollution and ensure adequate water quality for arowanas in captivity.

The filtration system must be efficient and powerful

Arowanas are large, highly predatory fish that produce a lot of waste. They are also sensitive to nitrates and toxins like ammonia and chlorine. Therefore, the filtration system for an Arowana tank must be efficient and powerful to prevent water pollution and maintain good water quality.

Firstly, the filtration system should be powerful enough to process all the water in the tank at a minimum of four times an hour. For example, a 150-gallon tank, which is the minimum recommended size for an Arowana, should have a filter with a flow rate of at least 600 gallons per hour (GPH). Power filters (or "hang-on-back" filters) and external canister filters are recommended as they provide effective mechanical, biological, and chemical filtration without taking up too much space.

Secondly, the filtration system should be regularly maintained and cleaned to ensure it operates efficiently. Monthly deep cleaning is necessary to remove debris and potential harmful substances. This includes cleaning the filtration components and vacuuming the substrate to eliminate detritus and waste that could affect water quality.

Thirdly, the filtration system should be paired with other equipment to create a stable environment for the Arowana. This includes an aquatic heater with a thermostat to regulate water temperature, as well as proper lighting to highlight the beauty of the Arowana and contribute to a healthier environment.

Finally, the filtration system should be supported by good maintenance practices. This includes performing routine water changes of no more than 10-25% of the total water volume every 2-4 weeks to maintain beneficial bacteria, as well as regularly testing water quality to ensure nitrite levels are close to zero. Overall, an efficient and powerful filtration system is crucial to providing optimal care for Arowanas and ensuring their health and well-being.

Water changes and full cleaning

Arowanas are highly predatory fish that produce large amounts of waste due to their high-protein diet. This waste can easily pollute the tank's water if not managed properly. Therefore, it is essential to perform routine water changes and full cleaning to maintain optimal water quality and a healthy environment for your Arowana.

Water Changes

Water changes are crucial to providing optimal water quality for your Arowana. It is recommended to change 10-25% of the total water volume every 2-4 weeks or as needed. Changing more than 25% of the water at once can be stressful for the fish, and draining the entire tank should be avoided as it will remove beneficial bacteria essential for the ecosystem.

When performing a water change, use a soft sponge or scrubber to clean the inside walls of the aquarium. Rinse your hands thoroughly before starting to ensure no harmful chemicals or residues are introduced into the tank. Do not remove the Arowana from the aquarium during cleaning, as this can cause unnecessary stress and potential injury.

Full Cleaning

A full cleaning of the tank, including vacuuming the gravel, should be done once a month or more frequently if the tank is housing multiple fish. After vacuuming the gravel, ensure that all décor is thoroughly dried and free from any bleach smell before placing it back in the tank. Add new, dechlorinated water at the same temperature as the existing water, and treat it with a water conditioner to remove toxic chemicals such as chlorine, chloramines, and heavy metals.

To maintain stable water quality, regularly test the water's pH, ammonia, nitrate, and nitrite levels using an aquarium test kit. Arowanas are particularly sensitive to nitrites and nitrates, so it is crucial to keep these levels in check. Additionally, provide proper filtration with a powerful filter that can process all the water in the tank at least four times per hour.

Water Temperature

Stable water temperature is also critical for the health of your Arowana. Use an aquatic heater paired with a thermostat to maintain the ideal temperature range of 72-82 degrees F, with fluctuations not exceeding +/- 2 degrees F in a single day. The wattage of the heater will depend on the tank's size and the ambient temperature of the room.

Other Considerations

• Avoid using household cleaners on any part of the aquarium, as they often contain ammonia and other chemicals toxic to fish. Use only aquarium-safe cleaners.
• Maintain moderate to strong water circulation to mimic the water currents and high oxygen levels found in the Arowana's natural habitat.
• Feed your Arowana a diet suitable for carnivorous, surface-feeding fish, including floating pellets or sticks, live/frozen/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.

Water conditioners to remove toxic chemicals

Arowanas are highly predatory fish that produce large amounts of waste due to their high-protein diet. This waste can easily pollute the tank's waters if the filtration system is not efficient and powerful enough.

Water conditioners are an essential tool to remove toxic chemicals from aquarium water, such as chlorine, chloramine, ammonia, and heavy metals. These chemicals are commonly found in tap water and can be harmful or even fatal to fish if not neutralized.

• Choose a reputable brand: Select a water conditioner that specifically states it neutralizes chlorine, chloramine, and heavy metals. Examples include Aquarium Co-Op Easy Dechlorinator, Fritz Complete Water Conditioner, Seachem Prime, and Kordon AmQuel.
• Follow dosage instructions: Read the product label carefully and follow the recommended dosage. In some cases, you may need to dose the water conditioner in a separate container before adding it to the aquarium.
• Test tap water: If your drinking water comes from a well or another untreated source, consider testing it for heavy metals. Some dechlorinators can remove these metals, but it's essential to know what you're treating first.
• Neutralize chloramine: Chloramine, a combination of ammonia and chlorine, is more stable and challenging to remove than chlorine alone. Dechlorinators are effective at neutralizing chloramine, but it may take a few minutes for the reaction to occur.
• Maintain water quality: Regularly test the water quality in your aquarium to ensure the conditioner is working effectively. Perform routine water changes (no more than 10-25% of the total volume) every 2-4 weeks to maintain optimal water conditions.
• Consider natural alternatives: While most conditioners contain chemicals, some products, like API StressCoat Natural, claim to neutralize chlorine with aloe vera. However, exercise caution, as there are mixed reviews about the effectiveness and safety of these natural alternatives.
• Enhance water hardness: If your aquarium water is very soft (low in mineral content), consider adding products like crushed coral, Wonder Shell, or Seachem Equilibrium to gently increase water hardness. This is especially beneficial for certain fish species that prefer hard water.
• Add beneficial bacteria: When setting up a new tank or adding new fish, consider using a product like Fritz Zyme7, which contains live beneficial bacteria to help purify the water from toxic waste chemicals.
• Avoid household cleaners: Do not use household cleaning products to clean your aquarium, as they often contain ammonia and other chemicals toxic to fish. Instead, opt for aquarium-safe cleaners specifically designed for fish tanks.
• Maintain optimal conditions: In addition to using water conditioners, ensure you provide optimal care for your Arowanas by maintaining the correct water temperature (72-82 degrees F), using a powerful filtration system, and providing a suitable diet of floating pellets or sticks designed for surface-feeding carnivorous fish.

Common diseases and treatments

Arowanas are large, carnivorous fish that produce a lot of waste. This waste can easily pollute the tank's waters if the filtration system is not efficient and powerful enough. Therefore, it is vital to keep Arowanas in a large tank with great water quality.

Ichthyophthirius multifiliis (Ich)

Ich is a ciliated protozoan that attaches itself to the Arowana's body, skin, or gills. It is vulnerable to medication only in the Tomont and Theront stages of its biological cycle. Increasing the water temperature to 30°C can accelerate their biological cycle, allowing treatments to target the Tomont and Theront stages.

Anchor Worm

Anchor Worm causes the insect's nervous system to turn from transparent to opaque white. The dead Anchor Worm will only drop off the Arowana after 2-3 days. Repeat medication and perform a 30% water change every 3 days. It is recommended to maintain the treatment for at least 2 weeks, even when the Arowana has recovered, to ensure the Anchor Worm has been eliminated. Increase oxygenation with an air pump during the course of medication.

Fish Lice

Fish lice are often introduced to the aquarium through new fish or 'live feed'. Symptoms include the Arowana constantly rubbing against surfaces or 'darting'. Quarantine new fish and reduce feeding of 'live feed' to minimize the risk of introducing fish lice. Dose OceanFree® '0' Anchor Worm & Fish Lice according to the recommended dosage. Repeat medication and perform a 30% water change every 3 days. Maintain treatment for at least 2 weeks to ensure the fish lice have been eliminated.

Bacterial Infections

Bacterial infections, such as Streptococcus, Vibrio, or Mycobacterium marinum, are caused by poor water quality or harmful chemicals introduced into the water. Symptoms include physical markings on the fish, physical injury to the eye, and hyper-production of slime due to poisoning or irritation. Maintain good water parameters and tank cleanliness. Remove uneaten food, conduct regular water changes, and do not overstock your tank. Minimize handling and choose compatible tank mates to minimize the risk of physical wounds and stress factors.

Unspecified Disease

An unspecified disease, possibly caused by a bacterial or fungal infection, initially affects the fins. The infected fish will scratch itself against the sides or bottom of the aquarium and its appetite will deteriorate. If the infection spreads to the gills, the fish may die. Treat by adding 1% salt & 0.8 grams of Quinine in every liter of water, using a commercial preparation sold in aquarium shops. Increase the water temperature by 2-3°C and increase oxygen levels. The Arowana should be fed nutritious food during treatment to build up its physical resistance. Upon recovery, disinfect the entire aquarium.

Drop Eye (DE)

DE is a condition that causes the eyes of the Arowana to bulge or pop out. It is more common in larger Asian Arowanas and is rarely found in smaller Asian Arowanas, African Arowanas, or Black Arowanas. There is currently no cure for DE, and the exact cause is unknown. However, it is believed to be caused by genetics, fatty foods, head trauma, or light reflections.

Frequently asked questions