LED lighting is a fairly new development in the world of fishkeeping, but its affordability, energy efficiency and ideal light spectrum make it a perfect choice for aquaculturists. LED light fixtures give aquariums a marine-like, blue-violet ambience similar to moonlight; in fact, these fixtures are commonly used as night-lights for saltwater aquariums. Unlike fluorescent and metal halide bulbs, LED bulbs are subtle and relatively dim. However, because of their high-wavelength light spectrum, LED bulbs are surprisingly useful for growing plants of all kinds, including notoriously temperamental species like red African hygro.
Set up the LED fixture so the light shines over a broad area of the tank. Do not light the aquarium from the side or corners; this may provide an interesting effect, but it doesn't provide adequate light for photosynthesis.
Select plants that are appropriate for your aquarium's size and chemistry. Recognise that most aquatic plants will not thrive in a saltwater or brackish environment. Easy-to-grow plants for beginners include water sprite, Java fern, Java moss, anubias and duckweed. These aquatic plants effectively increase dissolved oxygen in the water and help to remove nitrates; however, they are undemanding and thrive with little care.
Root the plants in a quarter of an inch of gravel (or the smallest amount necessary for keeping the plants in place). Understand that aquatic plants tend to rot or die prematurely if they are rooted too deeply.
Leave the LED lights on for 14 to 18 hours per day while the plants acclimate to their new environment. Reduce the amount of light at a rate of one hour per week until the tank is lit eight to 12 hours per day; this range is ideal for most fish and aquatic plants.
Check levels of nitrate, nitrite and ammonia at least once per week to ensure the health and vitality of your fish and invertebrates. Note that thriving plants generally reduce levels of these pollutants. Remove any dead or decaying plant matter from the tank promptly to prevent toxin build-up.
Always use caution when handling electrical equipment, especially if your hands are wet.