The lights from aquarium lighting produced energy for aquarium plants to living and needed for metabolism. Stronger aquarium lighting will make the faster plants growth and increasing pH-value of aquarium water, and require more CO2 including other nutrition which needed for plants to living. Conversely, if the aquarium lights are not strong enough, while a large amount of CO2 given and making the levels of CO2 in the aquarium would be excessive, consequently photosynthesis of aquarium plants can not be properly.
Since photosynthesis takes place in the presence of light, light is a necessity for healthy plants. Natural sunlight is made up of a number of light waves that have different wavelengths. The plant pigment chlorophyll will absorb only certain light waves.
Sunlight will promote the growth of algae. Long exposure to sunlight will also heat up the water. Artificial light is therefore more advisable for plants growing in a aquarium. Full spectrum or broad spectrum fluorescent light is best suited for plant growth. Aquariums usually need about 1.5 watts of light per gallon of water and about 12 hours of light per day. Of course, if your aquarium is deep, you may need additional wattage, and need to keep the light on for longer hours. Using light colored gravel is a good way to create a light bottom for a deep aquarium.
The wattage of light required for healthy growth in plants is also species dependent. Some plants, like the Anubias, Java Fern and Java Moss, require only low to moderate lighting. So, a single fluorescent tube will give enough light for these plants. The Water Wisteria, the Indian Fern, the Water Lily, and the Waterweed are some plants that need bright light. These plants will require at least one additional fluorescent tube to survive and flourish. Some species like the Bacopa and the Cabomba require extra strong light. These plants are of course not very suitable for beginners.
However, the nature of aquarium plants related to the light intensity basically divided into two groups:
- Aquatic plants require low light intensity, such as Anubias, Microsorium, Bolbitis, and Cryptocoryne. These plants are kind of easy to maintain because they don’t need lots of light and Carbon dioxide.
- Aquatic plants require high light intensity, such as Rotala, Red Ludwigia, Cabomba, and some kinds of Echinodorus species. These kinds are hard to maintain and need lots of light and Carbon dioxide. These aquatic plants can not also grow well under the light with low intensity.
Knowing the nature of aquatic plants related to the light intensity is important for Aquarium decorations. If we want to decorate the aquariums, then the water plants which require high light intensity placed under the aquarium lighting, and the low light plants placed in the shade areas. If we placed the aquarium plants without considering the light necessary, certainly the aquatic plants growth will be disturbed. For aquarium decorations which combined two kinds of the aquatic plants above, and with the strong light of the aquarium lighting, so the plants growth will be looks like this.
Firstly, the aquatic plants which require high light intensity such as Rotala and Cabomba will grow well. Whereas the low light plants such as Cryptocoryne and Microsorium will be stable. After the light intensity of "aquarium lighting" is reduced, for example after 6 -12 months, then the type of "aquarium plants" such as Cryptocoryne and Microsorium will grow well, and the growth of Rotala or Cabomba will increasingly stunted.