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How To Protect The Fish Tank From Sunlight?

Once I visited my friend’s place and he had a 20-gallon fish tank close to the window. When the sun came up sunlight directly pour into the fish tank. I also observed all the fish were trying to hide from the hot sunlight. It was clearly uncomfortable for them. So I talked with my friend and guide him on ‘How to protect the fish tank from sunlight. Here I am going to share those guidelines with you. And talk more about fish tank sunlight protectors.

How to protect the fish tank from sunlight

What is a fish tank sunlight protector?

Though sunlight is essential for plant-growing aquariums, prolonged exposure to sunlight in an aquarium causes many problems. They are uncontrolled algae growth, temperature rise, and evaporation. Despite this, direct sunlight may harm the eyes and skin of some species of fish. Further, the overheating generated by direct sunlight is deadly to the fish. However, there are some fish species, such as tropical fish who enjoy the sunlight too.  

A fish tank sunlight protector is a remedy to avoid direct sunlight. It may vary from a piece of cloth to reflective tinted glass spending on the intensity of the direct sunlight and the fish species.

Why do you need a fish tank sunlight protector?

Avoid Direct Sunlight

This is the simplest way to protect your aquarium from the sunlight. You just need to place your aquarium in a closed, covered space or indoors for their protection and direct daylight.

Direct sunlight causes high light intensity and it may harm the eyes and skin of fish. Besides, the heat generated from direct sunlight increases the temperature of tank water in the tank and the high temperatures increase the stress of the fish and ultimately negatively affect their health

Place the fish tank under the staircase

This also avoids the direct sunlight, which causes health problems for your fish. On the other hand, because the space under the staircase is covered from two/three sides, the opportunities to get heated by the sunlight are low. Also, even if you have to cover the aquarium, in the case of high-intensity direct sunlight, you have to cover only one side as all other two or three sides are already covered by walls. Besides, the atmosphere under the staircase is a little bit cooler than the other places in the same house. 

Place the aquarium in Greenhouse

Placing your aquarium in a greenhouse is another good method to avoid sunlight. A greenhouse is used to grow plants in closed and controlled surroundings.  This is the best place to cover your aquarium in cold weather. The important thing is greenhouse lets sunlight get through glass and makes the temperature rise inside the greenhouse.

Switch the Fish Tank Position on the North or South Side

Sunlight contains harmful radiations such as Ultra Violet (UV)  and Infrared (IR). These rays are harmful to the fish also and therefore, you need to keep your pets away from bright daylight to ensure their safety. Placing your tank on the North-Southside will protect it from the sun rays directly hitting the aquarium tank.  

Due to the sun’s movement, the tank will get direct sunlight if you face the tank on the east-west side. Therefore, switching the tank position on the North or South side will keep your tank away from the bright sunlight making it safe from sunlight.

Use Curtains

If you think us look to your lounge you can place the fish tank in there. But that might expose your fish tank to sunlight continuously. Direct sunlight may harm your fish and the easiest way to avoid sunlight is to use curtains on windows and doors and keep them closed. The curtain will help to block sunlight direct exposure and make the room cooler and bearable for fish.

Use Reflective Tinted Glass

Using reflective tinted glass is another option to avoid sunlight which makes your aquarium warm. Further, it reduces the algae growth and hence, it keeps the look of your aquarium. 

 However, if you use the aquarium to relax from the view and beauty of fish and other creatures, you lose that benefit by covering the tank with reflective tinted glass. Alternatively, you can replace back glass of the fish tank with tinted glass to reduce direct sunlight. This is more economical than covering all four sides and also you can watch the behavior of your pets from other sides.

Use Tinted Glass Windows

This is an alternative to the previous method of using tinted glass or the aquarium. The advantage of this method is, it does not harm your view. In most cases, sunlight falls on fish tanks and comes out of the windows. The advantage of using tinted glass is it does not completely block the sunlight but reduces its intensity of sunlight. It keeps the sunlight to an acceptable level which is necessary for the healthy growth of plants and also the fish and other creatures of the aquarium.

Use Blinds on Windows for sunlight

As described earlier, windows are the most common places for sunlight to enter your room. Therefore, it is easy to use a method to cover your windows. You can even keep your fish tank away from the windows to avoid harmful sunlight.

However, keeping a tank in the middle of your room or living area may restrict the space that can be utilized for another purpose. Therefore, you can use several methods to cover the window. Using blinds is such a method and you can partially block the intense sunlight entering the room and directly falling on the aquarium by using blinds.

However, using blinds may be expensive. You can paste paper sheets or use newspapers on windows to block sunlight and heat in the room as an alternative DIY method to block sunlight. It does not cost like blinds and also it is good to reuse paper items to save nature.

However, if you do not like the used newspapers to cover windows, you can always use decorated pares with floral patterns to cover the windows. This will protect your aquarium from sunlight through the summer.  

Use Tank Cover

Using a tank cover is one of the best DIY methods. What you can do is, you can purchase a piece of fabric that matches your living area and sew it with the measurements of the fish tank. It will add glamour to your lounge, and cover your beloved fish from direct sunlight.

This also blocks the view of your tank; you need to take it away to look at your pets. Therefore, you can just remove the cover in the evening till morning to enjoy the view of your aquarium.  You can also use a lid to cover the top of the tank. This helps to stop your fish from jumping out from the tank too. There are many DIY methods to make a fish tank lid your own.

How to protect the fish tank from sunlight

Use Thermal Insulation to protect the fish tank

Apart from the excessive algae growth, resulting from excessive sunlight, increasing the temperature of the water is a big issue for the fish and other creatures. Especially, if you are living in a tropical country, the temperature of the tank may rise higher than the recommended value in a short time.

It stresses the fish species and negatively affects their health. Thermal insulating materials are the solution for it. It ensures a controlled temperature environment. You can either use them on the top or around the aquarium or use them all around the tank including the top depending on the intensity of the sunlight falling on your tank.

These materials will provide thermal insulation and protection from sunbeams and harmful radiations directly falling on your fish tank.

Use Artificial Lights

The remedies we have discussed above partially or completely block the sunlight. Especially, covering all the doors and the windows, letting the room stay dark. Some fish species may feel unhappy staying in the darkness. Also, It can be a disappointing and tempting factor for some pet owners to remove curtains or other remedial measures discussed above. Therefore, to overcome the light issue you can use artificial lights. However, make sure the light sources you are using are not strong as it also stresses the fish and increases the temperature of the water. 

Grow Plants/Trees in Front of Windows

Growing plants and trees in front of windows will benefit three ways. Firstly, it partially blocks direct sunlight. Secondly, The shade of trees will prevent the temperature rise and bright daylight from entering the living area. Thirdly, it is an environment-friendly solution and costs nothing or less than the other methods. You can also place small flowering plants’ pots in windows to enhance the view. It is a long-term solution to reduce the impact of sunlight and temperature rise in your room while adding extra beauty.

Paint the back and top of the aquarium

If sunlight falls from the back of your aquarium you can paint the backside of your aquarium. It is better to use a light color because light colors do not absorb the temperature and hence do not increase the temperature of your aquarium. Alternatively, you can use thermal insulation along with the paint or install tinted glass. The top cover of the aquarium also can be painted if you are using glass as the top cover. 

Use sunlight-blocking film

This is a tinted UV film that helps to block direct sunlight and reduce heat. The advantage of sunlight-blocking film over other conventional methods is it looks clean on glass, so it will not block your view. Another advantage is less maintenance cost. You need to install the film outside of the aquarium glass. They are available in many sizes and you can buy films according to the size of your aquarium

is sunlight bad for fish tanks?

Solar energy or sunlight is the lifeline of all organisms in our ecosystem. Many fish species, especially tropical fish enjoy the sunlight. On the other hand, prolonged sunlight is not good for the fish from colder environments such as Clownfish guppies.  However, there are plenty of harmful effects of your aquarium being exposed to sunlight and associated radiation. The main effects are listed below.

Rising temperature

All aquatic pets require specific optimal water temperatures for their survival. They are cold-blooded animals and are extremely sensitive to temperature gradients.  When sunlight hits the walls of a water tank,  its interior temperature can rise beyond acceptable limits.

Water Loss

Sunlight causes a warmer environment in the fish tank which is a factor in the increase in the evaporation process. It not only causes a loss of water but also increases the humidity level in your room. Therefore, direct sunlight in the aquarium is not good.

Excessive Algae Growth

Sunlight is the essential ingredient for photosynthesis in the algae matter in aquatic environments. When there is plenty of sunlight, the algae growth will increase. It negatively affects the fish and other species in your tank as they will lose space due to increased algae volume. Further, your fish tank will not look great and get a junky appearance. Therefore keeping the aquarium in shades or indoors will save the aquarists from uncontrolled algae growth.

It is affecting some fish species. A variety of aquatic pets are shy and do not like bright lights. Especially if you have nocturnal fish species, they get stressed by bright light. 

Damage fish 

If direct sunlight falls on your aquarium for a prolonged time, it can literally burn the fish. This will damage their eyes and skin. However, if you have plants in your aquarium they need sunlight. It can be concluded that bright or direct sunlight for prolonged periods is bad for the fish.

How to protect the fish tank from sunlight

Can you put a fish tank in direct sunlight?

It depends on several factors. Firstly, if you have tropical fish, they will enjoy the direct sunlight and brighter environment. On the contrary,  fish from colder environments and nocturnal species will get stressed by the bright light.  Secondly, the time period that fish are exposed to direct sunlight also matters. Even tropical fish get stressed if they keep in direct sunlight for many hours.

Thirdly, If you have live aquatic plants in your aquarium, most of them do well in direct sunlight while so do not. Therefore, you need to study well about the plant varieties in your aquarium. In conclusion, you can put the fish tank in direct sunlight, after considering favoriting of fish, plants and other creatures in your tank. However, make sure you don’t keep the fish tank exposed to direct sunlight for a long period. 

How much sunlight does a fish tank need?

Fish need 8-12 hours of light a day. Although three is no need to provide them with natural sunlight, it is the best light source for them. The need for light sources for many fish species is to maintain a day-night routine. However, direct sunlight will cause the water to overheat and the algae to grow too quickly.

It can also give your fish sunburn. If you have a planted tank, it requires more sunlight, as plants and beneficial algae use it for photosynthesis. This provides fish with the oxygen they need to stay alive. They also get vitamin D by nibbling on the plants, keeping them healthy and their scales bright and vivid.

Credit to : JBM Aquayard

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About Dr.Chamika

Hello, I'm Dr. Chamika. I am a Researcher in Water quality, Aquatic organisms, and Environmental chemistry. I am a passionate fish keeper, with10 years of experience. My mission is to help other aquarists experience the joy of fish keeping.