Best Light Spectrum for Aquarium Plants

Aquarium plants need the right light spectrum to thrive. The light needs to be a sufficient intensity, which is different from the wattage. The best aquarium lighting will produce high intensities but it may also hinder your fish and not provide enough color separation of plants.

Most aquarium plants are photosensitive and need a light that falls within the blue, green, and red spectrum. While some plants can tolerate a wider range of light, others are more specific and will do better with a specific light spectrum. It is important to choose a light spectrum that corresponds with the plant’s natural habitat. In general, you might want to consider low-wattage lights for indoor use or using LEDs with UV filters to protect against algae build-up on solid elements like LEDs used inside their tubes that emit blue wavelengths only at very low intensities.

Top Light Spectrums for Aquarium Plants

Blue discosoma (Actinodiscus – soft coral) coral in a reef tank


The blue light spectrum is the longest and contains the most energy of all the colors of light. This is why blue light is the best light spectrum for aquarium plants. It stimulates growth and helps to promote coloration in plants. In addition, blue light does not trigger photosynthesis or makes your plants grow poorly. Some plants, like Anubias nana, appreciate low-wattage blue lights which mimic the light they receive in their natural habitat.


The most common light spectrum used in aquariums is the green spectrum. This is because it is the most natural light that aquarium plants are used to. It is also the most beneficial to their growth. In addition, it is the prime light for nurturing photosynthetic growth in plants. Aquarium plants that thrive in bright green environments need exposure to high intensity of green light. This wavelength is found naturally in sunlight and plant chromosomes use it to change energy into chemicals needed for photosynthesis.

Rainbow, Tropical Climate, Sea Anemone, Mermaid, Sea


Some aquarists believe that red light is the best light spectrum for aquarium plants. This is because red light is thought to be more beneficial than other colors when it comes to planting growth. Additionally, red light is the primary color that human eyes see. So it is important to use a light spectrum that corresponds with how humans perceive colors. If a plant can’t get enough have or needs more red light you should use LEDs with UV filtering as well to prevent algae growth on solid aluminum parts of the fixture and can still grow healthier plants in thermally efficient fluorescent lighting.


Yellow is not as beneficial for aquarium plants as the other colors mentioned. Some aquarists find it to be harmful because it stimulates excessive growth in plants. This can lead to algae problems and stunted growth. For most Aquarium plants yellow light should only be used sparingly if at all, especially when paired with blue or red LEDs since these colors stimulate higher levels of photosynthesis than yellow light does from plants. While this is not the most commonly used light spectrum in keeping aquatic species or freshwater fish, it does have some benefits that are worthy to mention. Plants can survive but they will perform poorly and cease growth if supplied with intense ultraviolet (UV) radiation from their lighting systems.

The view of freshwater aquarium with tropical fishes, shrimps and water plants

How to Choose the Best Light Spectrum

When it comes to choosing the best lighting for aquarium plants, there are a few things to consider. The type of light your plants receive will impact their growth and health, so it’s important to choose the right kind. Before purchasing any type of light, you must know the spectrum and lumens. The spectrum is a measurement used to classify colors as blue, green, or red by how many wavelengths they contain. Lumens are units that measure the amount of light output in watts produced per square inch.

Adjusted Light Intensity

Adjusting the light intensity for aquarium plants can be a difficult task. However, by adjusting the light spectrum, you can provide the plants with the correct amount of light. Different plants require different light spectrums to grow optimally. By knowing what light spectrum your plants require, you can adjust the light intensity accordingly.

Harmonized Color Spectrum

One of the best light spectrums for aquarium plants is a mix of red, orange, yellow, green, and blue light. This spectrum is called the “harmonized color spectrum.” It is the most natural and beneficial light for aquarium plants.

Balanced Spread

Aquarium plants need a balanced spread of light and color to thrive. Too much light will kill plants, while too little light will not provide enough energy to the plants and they will not grow. It is important to find a light spectrum that is appropriate for the plants you are keeping. Some plants need more blue light, while others need more red or yellow light. It is important to experiment with different light spectrums to see what works best for your plants.

Visually Enhancing

Many different types of light spectrums can be used to visually enhance aquarium plants. Some light spectrums are better for certain types of plants, while other light spectrums can be used to improve overall plant health and growth. It is important to choose the right light spectrum for your aquarium plants so that they can thrive and look their best.

Color Temperature

Light is the most important element in aquarium plants. Making the right choices when selecting a light spectrum and color temperature for your aquarium plants can help them thrive. A color temperature of 3500K to 7000K is ideal for keeping plants healthy and vibrant, while a lower temperature of 1800K is better for plants that need less light. A higher temperature is better for plants that require lots of light and heat, while lower temperatures are better when your aquarium needs less nutrient uptake.

What Are the Effects of Lights in a Planted Aquarium?

Lighting effects for a planted aquarium can be greatly affected by the type of light fixture used. Halogen, LED, and fluorescent lights all produce different light spectrums that can be beneficial or detrimental to the plants in your aquarium.

  • Halogen lights: These are the oldest type of light fixtures used in aquariums. They emit harsh, white light that is great for general illumination but can be detrimental to plant growth.
  • LED lights: These are becoming more popular because they produce warm, natural light that is good for plant growth and reproduction. However, they tend to be more expensive than other types of lights and may require more frequent replacement. A disadvantage with LED lighting is that the light radiates rays in all directions, making it difficult to control and direct towards specific plants resulting in a ‘halo of light’ creating an unattractive environment for aquarium fish.
  • Fluorescent lights: These are a popular choice for aquarium plants because they emit a wide range of colors, including blue, green, yellow, and red. This makes it easy to find the right light for your plants, and it also helps to keep them healthy and happy.
  • Fluorescent tube: Incandescent light bulbs produce harsh, white light that can damage the eyes and skin of fish and plants. A more natural light source, such as a fluorescent tube, provides a warm, yellow light that is better suited for plant growth. Moreover, fluorescent tubes are also safe for fish and plants. They do not produce as much heat compared to incandescent bulbs so they will help keep your tank at a healthy temperature.