Should You Cover the Sides of an Arowana Tank?

Have you ever set up a beautiful aquarium for your arowana but noticed it acting jumpy or nervous whenever someone walks by?

Covering the sides of an arowana tank helps reduce stress and sudden movements caused by external distractions. Limiting visual stimuli creates a calmer environment, supporting the fish’s natural behavior and promoting better health and overall well-being.

Understanding why your arowana reacts this way can help you create a peaceful and secure home for your prized fish.

Why Covering the Sides Helps Your Arowana

Arowanas are sensitive fish that react easily to movement and light changes around their tanks. When their surroundings are too open, they often feel exposed and unsafe. Covering the sides of the tank helps block out sudden movements, shadows, and reflections that may frighten them. This creates a sense of security, allowing the fish to swim more calmly and display natural behavior. Stress in arowanas can lead to health issues such as loss of appetite or injuries from jumping. By limiting visual disturbances, the environment becomes more stable and comfortable for them to thrive in.

It’s not about making the tank completely dark but reducing unnecessary distractions. A calmer environment means your arowana will feel more at ease and adjust faster to its surroundings.

When an arowana feels safe, it tends to eat better, display brighter colors, and move more gracefully. A peaceful environment encourages overall health and vitality.

Choosing the Right Type of Cover

Selecting the right cover depends on your tank’s setup and the look you want. Using opaque backgrounds or decorative panels on two or three sides can work well. Some aquarists prefer frosted film or natural-themed backdrops to reduce reflections without darkening the tank too much.

A balanced approach is best when covering the sides. Blocking too many sides can limit your viewing pleasure, while leaving everything open may stress your fish. Aim to cover the back and one or two sides for comfort and visual appeal. Avoid heavy materials that restrict airflow or make maintenance difficult. Simple, lightweight options such as vinyl sheets or aquarium backgrounds are ideal. If your arowana still shows signs of stress, try adjusting lighting and tank placement. Avoid areas with heavy foot traffic or sudden movement. These thoughtful adjustments create a stable environment where your arowana can feel protected and thrive comfortably.

Common Mistakes When Covering the Tank

One common mistake is covering all sides of the tank completely. This can make the tank too dark and limit airflow. Another mistake is using materials that trap heat or moisture, which can affect water quality and stress your arowana even more.

Some people also use reflective materials without realizing it. Reflections can confuse your arowana, making it think there’s another fish in the tank. This can lead to aggression or stress. Another issue is using strong adhesives or paints that release harmful chemicals. It’s safer to use aquarium-safe materials and avoid anything that changes water conditions. Proper ventilation and moderate lighting should still be maintained to keep the fish healthy and active.

Balancing visibility and comfort is key. Your arowana should feel safe without losing access to natural light. Covering just two or three sides is often enough to create a calm and controlled space.

Signs Your Arowana Is Feeling Stressed

A stressed arowana may start swimming frantically, hide often, or refuse to eat. You might also notice it jumping more than usual or rubbing against the tank walls. These are signs that the environment feels unsafe or overstimulating.

When your arowana shows these signs, check for bright lights, loud noises, or constant activity near the tank. Sometimes, stress can also come from reflections or poor water conditions. Adjusting tank placement or adding side covers can make a noticeable difference. Once the environment feels secure, your arowana will become calmer and more confident. You’ll likely see steady swimming patterns, regular feeding, and brighter coloration—all signs of a healthy and content fish.

Materials You Can Use for Covering

Vinyl aquarium backgrounds are a popular choice because they are easy to apply and remove. They come in various colors and patterns, allowing you to match your setup’s theme while still blocking unnecessary distractions for your arowana.

Another good option is frosted film, which reduces reflections and keeps the tank bright without overwhelming the fish. You can also use lightweight foam boards or fabric panels for temporary coverage. Just make sure they’re moisture-resistant and easy to clean.

Maintaining Proper Lighting

Lighting plays a big role in how secure your arowana feels. Bright or direct lighting can cause stress, especially if the tank is not covered on the sides. Soft, diffused light is ideal for reducing glare and reflections that confuse or frighten the fish. When adjusting lights, aim to mimic natural conditions with a consistent schedule. Avoid sudden changes that may startle your arowana. Using a timer helps maintain balance, and combining proper lighting with partial side coverage encourages steady behavior and healthy color display.

When to Remove the Covers

Remove the covers occasionally during cleaning or when observing your fish’s health closely. This allows you to inspect the tank and ensure the environment stays balanced. Once done, replace the covers to maintain your arowana’s sense of safety and comfort.

FAQ

Should I cover all sides of my arowana tank?
No, it’s not necessary to cover all sides. Covering every side can make the environment feel closed off and dark. It’s better to cover two or three sides, such as the back and one or both sides, depending on your setup. This approach gives your arowana a sense of safety while still allowing enough light and open view for you to enjoy watching your fish. It also helps maintain proper airflow and reduces condensation around the glass, which keeps the tank cleaner and more comfortable for your fish.

What materials are safe for covering the sides of the tank?
The safest materials are those made specifically for aquarium use. Vinyl backgrounds, frosted films, or aquarium-safe plastic panels are great choices. Avoid using materials that contain strong adhesives, paint, or chemicals that can release fumes or leach into the water. If you prefer a temporary option, moisture-resistant foam boards or fabric panels can work well too. The key is to make sure the material doesn’t interfere with tank ventilation or trap heat. Choose something easy to clean and replace when needed, so maintenance stays simple.

Can covering the tank sides affect water temperature or oxygen levels?
If you use thick or airtight materials, it can affect both temperature and oxygen levels. Arowanas need stable water conditions, so make sure your covers allow for airflow. Avoid sealing the top of the tank unless you have proper ventilation. Covers on the sides typically have little impact on oxygen, but poor ventilation at the top can lead to moisture buildup and unstable temperatures. Always monitor your tank’s temperature and water quality after making changes to ensure your fish remains healthy and comfortable.

Will covering the sides make my arowana less active?
No, it usually makes your arowana calmer, not less active. Stress often causes erratic swimming and jumping, which can lead to injuries. Once your arowana feels safe, its movements become smoother and more natural. You might see it swimming gracefully and exploring the tank more confidently. Reducing visual distractions doesn’t make your fish lazy—it helps it feel secure enough to display normal behavior. When arowanas feel comfortable, they also tend to eat better and maintain brighter colors, which is a sign of overall well-being.

How do I know if my arowana is stressed even with the sides covered?
Watch for changes in behavior. If your arowana keeps hiding, stops eating, or swims frantically, it’s still stressed. In this case, check the lighting, water conditions, and tank placement. Bright lights or constant movement nearby might still be triggering the stress. Try adjusting the room lighting or placing the tank in a quieter area. Covering helps reduce external distractions, but other factors like noise, tank mates, and water quality also play a big role. Regular observation helps you catch issues early before they affect your fish’s health.

Can I use decorative backdrops instead of plain covers?
Yes, decorative backdrops work perfectly fine as long as they’re non-reflective and safe for aquariums. Choose natural designs like plants or stones that blend well with your tank’s setup. Avoid shiny or glossy materials because they can create reflections that stress your fish. Many aquarists prefer printed backgrounds because they add style while still providing coverage. They’re easy to apply, affordable, and removable if you ever want to change the look of your tank. Always ensure the backdrop fits securely without gaps that could trap moisture or dirt.

Is it okay to remove the covers sometimes?
Yes, removing the covers occasionally is good for maintenance and observation. It allows you to inspect the tank’s condition, check your fish’s health, and clean hard-to-reach spots. Just make sure not to leave the tank fully uncovered for too long, especially if your arowana tends to jump. After cleaning, replace the covers to maintain that sense of security your fish depends on. Over time, you’ll find a routine that keeps both the tank and the fish in great condition.

Can I combine tank covers with lighting adjustments?
Definitely. Combining side covers with softer lighting creates a calm and natural environment. Use dim or indirect lights to reduce glare, and consider a timer to maintain a steady schedule. Consistent lighting helps your arowana adapt better and reduces sudden reactions to brightness changes. Many owners notice that when they combine proper coverage with gentle lighting, their fish become more active during feeding and rest peacefully afterward. It’s a simple yet effective way to support your arowana’s overall health and comfort in its tank.

Final Thoughts

Covering the sides of an arowana tank might seem like a small detail, but it plays a big role in your fish’s comfort and behavior. Arowanas are known for being alert and easily startled, especially in open environments where there is constant movement or changing light. When they feel exposed, they tend to jump, hide, or become aggressive. Adding side covers helps reduce these issues by limiting visual distractions. This simple adjustment can make a noticeable difference in how relaxed and confident your arowana appears. It’s a way to bring more balance to their environment without taking away from the beauty of your aquarium.

It’s important to remember that not every arowana reacts the same way. Some may feel secure even in open tanks, while others may become stressed with too much visibility. Observing your fish’s behavior is the best way to decide how much coverage it needs. If your arowana appears jumpy or refuses to eat, adding covers to one or two sides may help. On the other hand, if your fish already seems calm and active, you might not need to make major changes. What matters most is creating an environment that supports your arowana’s sense of safety while maintaining good lighting and water conditions. Balance is key, and small adjustments can lead to lasting improvements.

Maintaining a comfortable tank environment goes beyond aesthetics—it directly affects your arowana’s health. Stress can weaken a fish’s immune system, leading to illness or erratic behavior. By using the right materials, ensuring proper airflow, and managing lighting, you can prevent these problems before they start. You don’t have to make the tank completely dark or enclosed; even partial coverage can reduce stress and make a big difference. Pairing that with regular tank maintenance, consistent feeding routines, and stable water parameters will help your arowana thrive for years. Watching your fish swim calmly and display its natural colors is rewarding and shows that your efforts are paying off. Taking time to understand your arowana’s needs and making thoughtful changes to its environment ensures it remains healthy, comfortable, and confident in its home.