Do Guppies Need Light? What Kind?

Light is essential to all living things, including guppies. Guppies get light from the sun and prefer darkness at night in their natural habitat. Therefore, they should get the same conditions for proper growth and development in the aquariums.

Although guppies are used to natural light in the wild, they can still live with artificial light. They require light since they have a circadian rhythm and thus need light to determine when to sleep and wake up. In a day, you should give guppies 8 to 10 hours of light and 6 to 8 hours of darkness.

Continuous lighting or lack of light will tamper with their circadian rhythm, meaning they will not know when to sleep or wake up. 

When you light up the aquarium, you see guppies swimming happily, feeding, and mating. However, when you switch off the light, the fish will stay inactive and rest on the substrate at the bottom of the tank, at the water’s surface, or on plant leaves or decorations.

Guppies in aquarium

Why do guppies need light?

Light is vital because guppies have a circadian rhythm, and in their natural habitat, they are used to both light and darkness. It’s essential to mimic these conditions and give them the right amount of light to grow and function properly.

1. Safety

Guppies prefer a planted aquarium because they use the leaves to hide from aggressive tank mates and rest at night. They also play among the plants for exercise.

2. Health reasons

Light is an important component in oxygen production, which is a byproduct of photosynthesis. Guppies take up oxygen for breathing through their gills and release carbon dioxide, which the plants take. 

Light also helps the guppies stay healthy. Lack of light will cause stress leading to a low immune system and making them vulnerable to diseases. Light provides the fish with vitamin D.

Finally, light is essential because it enables guppies and other fish to maintain their pigmentation. Too little light for extended periods will make their scales fade and become lighter or white.

Do guppy fries need light?

Young guppies need light as much as their parents, if not more. They need light to grow properly and healthily. Too little light will cause the young guppies to be weak, and their spine may curve. 

You should provide light for about 10 to 12 hours to enable them grow strong. However, you should also give them 8 hours of darkness to allow them to rest. 

Guppy fries can live well with sunlight and artificial light, but you should not surpass their recommended light limit. You can buy an automatic timer to help keep the lighting issue in check.

What kind of light do guppies need?

Natural sunlight is the best form of light that exists and is good for guppies. However, like all other fish, guppies do not need sunlight biologically and can survive with artificial light. Sunlight is good for guppies because it has many health benefits but not direct sunlight.

Guppies require consistent water temperature; direct sunlight will heat the water, raising the temperature and affecting the fish. Direct sunlight will also cause sunburn affecting guppies’ quality of life. It will cause stress which can lead to death.

Protecting the guppies from direct sunlight is important if you intend to use natural light. Avoid keeping the tank beside a window and put enough plants and accessories for the fish to shelter themselves when the light is too much.

Guppies are little beautiful creatures that most aquarists keep as a hobby. To enjoy their beauty, you need good light to illuminate them. Also, sometimes they are affected by diseases and injuries, and it will be hard for you to see if the tank is not bright enough.

The following are the right kind of artificial lights to use:

1. LED lights

LEDs (Light-Emitting Diodes) are cheap to run, efficient, and long-lasting. There are numerous options for LED lights in the market, so you can choose what fits your guppy tank.

LED lights come in many colors and spectrums and do not produce heat. The kind of LED light you purchase depends on whether you have live plants.

2. Standard fluorescent lights

Standard fluorescent lights come in the traditional long tube and are available in different spectrums and ranges. They are energy efficient and produce minimal heat, so they will not heat the water. 

3. Compact fluorescent lights

Compact fluorescent lighting systems are similar to standard fluorescent lighting but have two smaller U-shaped tubes. They are brighter than the standard fluorescent bulb and are available in various spectrums and sizes.

4. Metal halide

Metallic halide lighting is mainly preferred for planted aquariums due to its intense illumination. It’s ideal for guppy and plant tanks, especially deep tanks. It also mimics natural sunlight with its brightness and wavelength. 

However, metal halide lighting produces heat, consumes more energy, and is not ideal for small tanks. In fact, most beginner aquarists will struggle to use it. Metal halide lights are relatively heavy and must be hung from the ceiling or on a stand. 

Choosing the correct bulb for your guppy tank size is important. Each tank has specific light needs depending on the size, depth, and inhabitants.

For example, in a fish-only tank, the lighting needs are minimal because you only need to illuminate. However, if your guppy tank has live plants, you need light with the right spectrum for photosynthesis. 


Guppies need light to grow healthy but not necessarily natural sunlight. You can use artificial lighting like LEDs, fluorescent, and metal halide. 

When choosing light for your guppy tank, you should consider the size of the tank, depth, heat output, and other tank inhabitants. If the tank is planted, you should consider a light with a spectrum that will enable photosynthesis.

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