Lighting explained

[jackpike]

Lighting explained

Lighting Like all plants, aquatic plants require light for photosynthesis to take place. As aquarists we have to replicate sunlight as closely as possible. There are several types of lighting available tungsten, fluorescent, Mercury Vapor or metal halide. It is important to use the correct strength and spectrum of light for your plants needs. Provide at least two Watts per gallon. From what i have read from other sources and my own personal experience, Gro-lux fluorescent tubes that cover the red light spectrum are not generally suitable for aquatic plants, there great for growing tomatoes but not aquatic plants.

Tungsten (Incandescent) These are the same bulbs you use in your home. Incandescent bulbs use a tungsten filament which glows hot as voltage passes through it. Incandescent bulbs produce a lot of heat per watt of output, are inefficient and tend to burn out rapidly. There are some incandescent bulbs used in inexpensive aquarium light fixtures for small freshwater aquariums.

Fluorescent Fluorescent lighting is very efficient compared to incandescent lighting. It produces more light per watt and far less heat and so is ideal for general aquarium use. Usually comes in either single or multiple tube configurations, depending on the height and size of the aquarium. Fluorescent tubes should be changed every 8 to 12 months because the output and colour spectrum will drop as the tubes get older.

Mercury Vapor These lamps look like metal halide units. Mercury vapor lamps produce strong green, yellow and orange wavelengths, which creates a good visual impression in the tank. but produces very weak blue wavelength light that is needed by many invertebrates, so you should use a blue fluorescent light if you keep invertebrates.

Metal halide Metal halide lamps produce so much light, that like the sun. A metal halide lamp should never be viewed directly. They have two drawbacks. The ballasts and metal halide lamps produce a lot of heat and use a lot of electricity. Adequate ventilation is required to stop aquarium water overheating, If there is inadequate ventilation, an aquarium chiller will be required to maintain a safe water temperature. Metal halide bulbs come in various color spectra, from 5500K to the 10,000K and 20,000K lamps.

Duration The correct type of lighting for your aquatic plants is no use if it isn't on for long enough. Aquatic plants in the hobby originate from different locations all over the world because of this different plants require different durations of light. But lucky for us plants can adapt, so as a rough guide lights should be on for about 12 hours per day. This of course is not a hard and fast rule, the 12 hour rule can be changed for your plants needs.