Do Fish in Aquaponics Systems Need Light?

Aquaponics is a symbiotic relationship between fish and plants where they require each other in order to survive. Fish provide nutrients for the plants to thrive, while plant roots clean water for the fish to live.

Light is a requirement for plant growth, and scientific studies have found the effectiveness of using artificial light on plants. However, many new aquaponics growers are unsure if fish also need light. This leads to the question, do fish in aquaponics systems need light?

This article will discuss the fish in your aquaponics system and whether they need light to survive. 

Do fish in Aquaponics Need Light

Even though plants need light, it is not necessary for the fish to grow and thrive in an aquaponics system. However, they need a period of light and darkness. Without changes at night or day, some fish may become sluggish, stop eating or become sick. Based on the location of your aquaponics system (indoors or outdoors), you need to provide your fish with the right type of light to avoid fish stress and diseases

If you have an outdoor aquaponics system, you may not need additional lighting because you can use sunlight and night. But if your system is indoors, and the light is limited, you will require additional lighting. 

Fish Tank in Aquaponics Systems

Why Fish Need Light in Aquaponics

Fish only need light to see their food. Fish and other aquatic animals are sensitive to light, and new research shows that light intensity, duration, and wavelength can contribute to fish productivity, activity, and overall health. However, exposing your fish to the right amount of light can help with egg development and health and help fish avoid stress and diseases. 

Choosing the Right Light for Your Aquaponics Fish

The amount of light given to fish in aquaponics systems should be the right level to prevent algae growth and fish stress, as fish can experience fear and stress when a dark tank is suddenly exposed to light when uncovered. The ideal lighting condition should be indirect natural light through shading or the right amount of artificial grow light.

How Much Light Do Fish in Aquaponics Need?

The amount of light fish need depends on the fish species you are raising in your system and the overall environmental conditions of your aquaponics system. However, as a general rule, most aquaponics fish need at least 12 hours of light each day. To fully understand how much light your fish need, you need to consider the following factors:

  • Natural light conditions
  • Temperature and climate
  • Fish species

Natural or Artificial Light Source for Your Aquaponics Fish

Both natural and artificial light are beneficial for the fish. You can choose either one of them depending on your need.

  • Natural Light Source

If you live in a location where there is an abundant light source, you can use that to your advantage and oft for using the natural Light. However, too much sun exposure can be dangerous to your fish. So avoid too much sun exposure to your fish tank by placing it in a shaded area or using an additional covering such as a fishnet or tent. Doing this will protect your fish from too much heat and algae growth.

  • Artificial Light Source

An artificial light source can be used in your aquaponics system if you have an indoor aquaponics setup or if your fish needs additional Light to thrive. 

What Aquaponics Fish Species Need Most Light?

Below is the list of aquaponics fish species and their Light requirements.


Fish Species   Light Requirements (Hours)
Tilapia 18 hours
Perch 16 hours
Koi 12 hours
Goldfish 12 hours
Guppies 12 hours


There are other popular aquaponics fish species that cannot tolerate bright lights, and it is recommended to use a minimum amount of light. These are:


Tilapia in a Fish Tank

Choosing an Artificial Source of Light for Your Fish

If you have an outdoor aquaponics system, you may not need additional light since you can use natural daylight and night. However, if your system is indoors or undercover, where light is limited, you will need additional light. 

Factors to Consider in Choosing Artificial Light

1. Light Distribution: Consider getting an artificial light that has vast light distribution. This is important because lights can naturally increase the water temperature in the fish tank. If the light distribution is not equal, not all portions of the water will be heated, and sudden changes in the temperature can cause fish stress.

2. Easy Installation and Maintenance:Choose artificial lights that you can easily install and maintain. So that when something goes wrong, you can quickly fix it.

3. Timer: As mentioned above, fish need light and darkness, so never leave your light on for 24 hours. As much as possible, try to mimic the natural environment where there is light and dark. Too much light could also promote algae growth in your fish tank.

Here are the light options for your aquaponics system:

1. LED Light

Light-emitting diodes are the best in the market today. We recommend getting an LED light where you can adjust the intensity easily on what your fish requires. Furthermore, LED offers a distinct advantage over the other grow light choices. These are:

  • Lack of heat - you can put the Light closer to your plants without burning the leaves. 
  • LED grow lights only emit Light that is usable to plants.
  • Energy-efficient.
  • Long life. 

In using LED, there is no need to use ballast, reflectors, or running cables since all the electronics are within the unit. LED grow lights can be used in tight spaces and operate at a lower temperature so that you can easily control your system’s temperature.

One disadvantage of LED light is that it is expensive, but if you want to invest in a long-lasting, efficient light, LED lights are a superb choice.

2. Fluorescent Grow Lights

Fluorescent lights are cost-effective and suitable for smaller-scale aquaponics setups. They come in various forms, such as T5 and T8 tubes, and provide sufficient light for growing leafy greens and herbs.

3. High-Intensity Discharge (HID) Lights

HID lights include Metal Halide (MH) and High-Pressure Sodium (HPS) lights. These are powerful lighting options suitable for larger indoor aquaponics systems. They deliver intense light output, making them ideal for fruiting and flowering plants.

Conclusion: Do Fish in Aquaponics Systems Need Light?

The answers depend on the type of fish species you are raising and where your aquaponics system is located. If your system is built indoors or in a place with insufficient light, then you need an efficient lighting system for your fish and plants. However, if you have an outdoor aquaponics system with enough sun exposure, you don't need to add light to your fish. 

Knowing your system's needs can create a thriving ecosystem where fish and plants flourish in a mutual and sustainable relationship. Thank you for reading our article. If you want to read more about fish health and diseases in aquaponics systems, subscribe to our newsletter.



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