For a planted tank setup, there are many lighting options to choose from. See which type of lighting is right for your planted tank.
Installing adequate lighting is important regardless what type of aquarium you have, but it is even more essential in a planted tank. Aquarium plants undergo the process of photosynthesis during the time they are exposed to light. During this process, plants absorb carbon dioxide and expel oxygen. Without adequate lighting, plants are unable to complete the process of photosynthesis and, rather than seeing an increase in oxygen levels, your tank could become overloaded with carbon dioxide. In order to keep your planted tank healthy for both your fish and your plants, it is not only important to provide lighting but to provide the right type and amount of lighting. Before you can do this, however, you need to learn the basics of aquarium lighting for planted tanks.
The Importance of Lighting in a Planted Tank
Photosynthesis is the chemical process through which plants use the energy from light to convert carbon dioxide into organic compounds. In the home aquarium, plants absorb carbon dioxide through their leaves and, through the process of photosynthesis, convert it into simple sugars. Oxygen is a by-product of this process. At night when the plants are not being exposed to light, photosynthesis is reversed and aquarium plants engage in a process called respiration. During this process the plants in your tank will absorb oxygen and use it to break down food – the by-product of this process is carbon dioxide.
Based on this information, an amateur hobbyist might be tempted to leave the lights in his aquarium on all the time in hopes of keeping the process of photosynthesis going. In reality, aquarium plants only need about 10 to 12 hours of light per day and leaving the lights on any longer will not do any good. In fact, exposing your aquarium to too much light may lead to excessive algae growth. For the sake of keeping a balanced tank, it is wise to set your aquarium lights on a timer so they will remain on for up to 12 hours every day.
Types of Lighting for Planted Tanks
The type of lighting you choose for your planted tank can greatly affect the health and growth rates of your plants. If you try to cultivate a planted tank using a single, small fluorescent bulb you should not be surprised if your plants grow very slowly or die off rather than growing at all. There are several types of aquarium lighting recommended for planted tanks and you, as the hobbyist, can decide which type is best for your tank.
Standard Fluorescent – Standard fluorescent bulbs range in both size and color and offer an average bulb life between 6 and 18 months. This type of lighting is particularly popular among aquarium hobbyists because it is inexpensive and does not require additional equipment such as cooling fans to run. Another feature which makes these lights popular is the fact that they can be installed in tank hoods – they do not require a specialized lamp or mounting fixture. Though these bulbs can be used in planted tanks, they are best suited for plants that require low lighting and, as such, may not fulfill the needs of a fully planted tank.
T-5 HO (High Output) – These bulbs are simply another variety of fluorescent light. Unlike standard fluorescent lighting, however, T-5 HO bulbs produce high intensity light and come in a much more compact size. T-5 bulbs range in wattage from 24 to 54 and can last up to two years. Unlike some types of high intensity lighting, T-5 bulbs are cooler running and do not require a fan. These bulbs are best suited for both reef tanks and a freshwater planted tank setup that are less than 24 inches deep.
VHO (Very High Output) – Another type of fluorescent lighting, VHO bulbs are available in high wattages and have a longer life than standard fluorescent bulbs. VHO bulbs come in wattages between 75 and 165 and can last between 4 and 18 months. Because these bulbs are available in a variety of sizes, they are ideal for large planted tanks. The major drawback associated with this type of lighting is the heat they produce. In order to prevent the tank from overheating, a chiller or cooling fan may be needed.
Power Compact – This type of lighting simply refers to compact fluorescent bulbs. Many hobbyists prefer the smaller size of these bulbs over standard fluorescent bulbs because it is possible to position more of them over the tank. Compact fluorescent bulbs can be found in a variety of sizes at wattages between 10 and 130. These bulbs have one of the best longevities in aquarium lighting, lasting up to 28 months. Though compact fluorescent bulbs provide high-intensity lighting and a wide spectrum range, they also run hot and may require a fan.
Metal Halide – Metal halide lighting provides high-intensity lighting ideal for reef aquariums and planted tanks more than 24 inches deep. These bulbs typically last between 6 and 18 months and come in wattages ranging from 70 to 1000. This type of lighting offers the highest intensity along with a wide spectrum range. The downside to metal halide lighting is, of course, that it produces a great deal of heat. These lighting systems are popular among advanced aquarium hobbyists and should only be used in combination with a chiller or fan to counteract the heat they give off.
Tips for Planted Tank Lighting
Regardless what type of lighting you choose to utilize in your planted tank, keep in mind that full-spectrum lighting is recommended to ensure proper plant growth. When purchasing the lights for your tank, stick to a ratio of 2 to 5 watts per gallon of tank capacity. It is also wise to remember that some types of lighting, particularly metal halide lights, produce a great deal of heat and should be accompanied by cooling fans in order to avoid overheating your aquarium.
If you are concerned about energy efficiency, both T-5 HO and compact fluorescent lighting systems are among the most energy efficient options in aquarium lighting. T-5 HO lights give off more than twice the amount of light as standard fluorescent bulbs of the same size and, because they are small, you can fit more of them into the space above your tank. Compact fluorescent lights utilize a twin-tube design which puts out a higher intensity of light than standard fluorescent bulbs without producing a great deal of heat. This option is low-cost and very safe for use in a planted tank.