Which Light Color Is Best for Aquarium Plants
One of the most important parts of the survival and visual appeal of a healthy planted aquarium is the light. One of the many things an aquarist may ask is, "What color of light is proper to use for the aquarium plants"? Is it better to just use red, or just blue, or just white? Based upon scientific understanding and hands-on experience, this article will explain the answer to this commonly posed question and outline recommendations of the correct aquarium light.
What Kind of Light Do Plants Need for Photosynthesis?
Photo-synthetically active radiation (PAR), which falls between 400 and 700 nanometers in the light spectrum, is what is utilized by aquarium plants in order to achieve photosynthesis. The two best-utilized colors of light for plant photosynthesis are:
- Red Light (approximately 620-680 nm) promotes stem elongation, flowering, and fruiting, and increases the mass of the plants, and also provides deeper reds in red colored aquatic plants such as Ludwigia repens and Nymphaea rubra.
- Blue Light (approximately 420-490 nm) increases growth of leaves and chlorophyll synthesis, and compact plant shape, and is the ideal choice for stem plants and those needing stronger root growth.
- Green light is only used to a lesser extent as plants reflect much of this wavelength, and its use gives an aquatic plant environment a more natural 'green' coloration, avoiding an unnatural purple hue.
Pure red and blue light (giving a purple, magenta type light) promotes healthy plant growth but makes a very poor visual impact with a lot of distortion in color. The best answer, therefore, is a full-spectrum light based on a color temperature of around 6500K but with a modified emphasis on red and blue light.
Comparison of the Effects of Different Light Colors on Aquatic Plants
Here's a table to make it easier:
| Type of Light Color | How it influences the plants | The overall look to the viewer | When to use this light color |
| Pure Red Light | Stimulates vertical growth and boosts plant size | Creates a warm glow and highlights red tones | Tanks with foreground plants that need vigorous stem growth |
| Pure Blue Light | Promotes compact foliage growth and chlorophyll production | Delivers a cool blue-green hue, accentuating blue and green shades | For foreground plants and mosses |
| Pure White Light (6500K) | Supports balanced, steady growth and maintains natural plant morphology | Presents a natural, comfortable visual effect | All types of planted aquariums |
| Adjustable RGB Light | Allows flexible adjustment of red and blue light ratios for customized cultivation | Offers diverse visual effects with strong ornamental value | Hobbyists pursuing optimized tank landscape and aesthetics |
Key features of Best Aquarium Lights: Adequate PAR levels (mid-high demand planted tanks suggest mid-range PAR level around 30-50+), Full Spectrum, and adjustable intensity/timer function.
Recommended Product: Seaoura Aquarium Lights
If you're on a budget but need a lot of power and controllability, Seaoura lights for planted tanks are a good option and highly favored by many planted tank hobbyists.
The Seaoura aquarium light manual will generally offer these primary setup suggestions:
- The Daily mode. 6500K full-spectrum light and moderate enhancement of red/blue colors. Light should be set to about 60%-80% (depending on the depth of the water and what kind of plant you have).
- 24/7 Sunrise and Sunset. The light will be a warm white at the beginning of the day, then transition to full spectrum at mid-day, then gradually fade away in the evening. Light changes slowly, so the bloom of algae is reduced due to sudden light changes.
- Timer mode. Use for 8-10 hours per day (low to medium tech tanks) or 10-12 hours for high tech planted tanks. Pay attention. Do not set the light too strong when starting a new tank; the best effect comes with CO2 and fertilizers.
Seaoura series features a multi-row RGB LED mixed-light design that has excellent even light distribution and deep light penetration, and it is applicable for aquariums ranging from 30 to 120cm in length. If used properly and according to its application directions, aquatic plants such as the Hemianthus (Pearl grass), Hemianthus callitrichoides "Cuba", the Alternanthera (Dutch leaf), and the Saxifraga (Tiger plant) are fast-growing and colorful.
How to Choose and Use Aquarium Lighting for Plants
Choose Based on Tank Type
For low-tech tanks (without CO2), a full spectrum, low-medium lighting will suffice. For high-tech tanks: Invest in high-quality (best) Aquarium lights, especially if they boast high PAR and tunable spectrums.
Light Cycle and Brightness
Do not run lights for more than 12 hours (algae growth). Use ramp timers for natural cycles.
Common Problems
- Yellow/melting plants: light level to low or lack of red/blue spectrum.
- Algae blooms: light level to high or lighting period to long (first regulate water flow and nutrients).
- Colors not vibrant: use more red spectrum.
So, What Is the Best Color for Aquatic Plants
There isn't exactly a best color, but a suitable combination of a full-spectrum base color with added red and blue wavelengths. Full-spectrum lighting is ideally at about 6500K and works to fulfill the needs of plants while maintaining good visual standards of viewing, and is thus the preferred choice for the majority of hobbyists.
If you want an all-in-one option, I'd suggest taking a look at the Seaoura aquarium light, which provides good value for its price and performance. Picking suitable aquarium lighting for plants will not only provide your fish with something nice to look at, but you will soon end up with a vibrant underwater garden.
