That all depends upon which plants you have chosen for your aquarium. If you have chosen nothing but "Easy" plants, 10-20 lumen (0.25 to 0.5 watts) per litre is adequate. For "Medium" plants, we recommend 20-40 lumen (0.5 to 1 watts) per litre, while "Advanced" plants require more than 40 lumens (1 watt) per litre.
Do LED lights cause more algae in an aquarium?
Without aquatic plants, low light conditions will favor the growth of algae, since there is no competition for the light or other nutrients. In freshwater planted aquariums, the use of Marineland Aquatic Plant LED Lighting Systems will promote the growth of plants, which will restrict the growth of algae.
Are LED lights suitable for growing plants?
Plants respond favorably to specific wavelengths in a light spectrum. In contrast, LEDs have the ability to produce wavelength specific light. This is the biggest advantage of LEDs in the indoor growing market. Because each LED emits a specific wavelength, growers can now optimize lights for plant growth.