LED Lighting for Your Freshwater Aquarium Pros and Cons

aquarium with LED lighting

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The right lighting is essential for a healthy freshwater aquarium. Light-emitting diode (LED) lighting has many advantages for your tank. Your options for this type of lighting are numerous, so you have more choices than the traditional incandescent, fluorescent, or metal halide lighting. But you will need to choose wisely to ensure you get lights that are bright enough and have the right spectral range to support the plants in your aquarium and keep algae growth minimized.

LED vs. Other Lighting Options

Your best lighting options for freshwater aquariums are standard fluorescent bulbs, compact fluorescent bulbs, metal halide lights, and LED lights. You want to avoid incandescent bulbs as they are suitable only for small aquariums and can give off too much heat.

Standard fluorescent lights supply good light intensity and produce little heat. Compact fluorescent bulbs give more light output (at a smaller size) and are often built into an aquarium hood. Metal halide lights have the advantage of having a full spectrum, so they are good at replicating the tropical lighting that many freshwater fish had in their native environment and can sustain photosynthesis for aquarium plants. However, they can produce a lot of heat.

By contrast, LED lights run much cooler than standard fluorescents and metal halides. They have many customizable lighting colors and intensities and will do well with both fish-only and planted tanks as long as you select those with the right output.

LED Lighting for Aquariums

The Spruce / Grace Kim

The Pros

You may want to set up a new tank with LED lights or replace the lighting system on your existing tank to take advantage of the benefits from this type of lighting. These include:

  • Low energy consumption: They take less energy to run—quite a bit less. LED aquarium lighting uses less electricity than other aquarium lights. Your energy cost savings alone will make up the difference in the cost of LED system in the first year to 18 months.
  • Low heat output: LED lights do not generate the heat that incandescent and fluorescent light bulbs do, so they won't heat up your aquarium water. However, they still need good air circulation so the heat they put off doesn't degrade the lifespan of the LED chip, and keep them away from other types of lighting that produce heat.
  • Long life: A very popular advantage of LED lights is the fact that they last far longer than other traditional types of lighting. LED lights last for up to 50,000 hours (almost six years) as compared with four to 12 months for incandescent bulbs, six to 18 months for standard fluorescent bulbs and metal halide bulbs, and up to 28 months for compact fluorescent bulbs. While they cost more initially, you will save the money you would spend in replacement bulbs over five years for metal halide, T5, or compact fluorescent bulbs.
  • Adjustable light intensity: LED lights can be dimmed and programmed, allowing for a natural dimming at sunset and the reverse at sunrise. This is particularly good for nocturnal fish, as a dim blue light can be left on the tank to simulate moonlight and allow for feeding and viewing purposes. There are even LED lighting strips that replicate the monthly lunar cycle. You can have fun changing the light with the remote or using an app on your phone. Or, let your smart lighting system determine the temperature and the stage of plant growth and select the right colors and wavelengths.
  • Color options: LED lights come in a variety of colors, which can be used to accent the tank in interesting ways. They are marketed by spectrum (often in the Kelvin or K system), and you can choose which suits your purpose. For example, 8,000K white spectrum promotes photosynthesis of your plants and enhances the colors of orange, red, and yellow fish. Add a magenta or magenta/blue LED and you also bring out greens, blues, and reds while proving more support for your plants. The 12K white and magenta combination can be perfect for planted aquariums. If you want a night lunar light that will make your fluorescent fish glow, 445-nanometer royal blue lights are popular. There are even arrays with different colors of LED lights you can program for your needs.
  • Coverage: Because LED lights are usually arrayed in a strip, you can get coverage over a wide area of your aquarium.

The Cons

LED aquarium lighting has a few cons, but you do need to take some limitations into account.

  • Availability: Many aquarium kits that include a light or hood with a light do not offer LED lights. Popular combination units, such as the Eclipse systems, are only offered with standard fluorescent light bulbs. However, you can find LED options to retrofit your Eclipse hoods. Likewise, some light fixtures are still offered with fluorescent lights.
  • Cost: LED fixtures tend to be a bit more costly to purchase up front. Your initial budget will need to be higher, even though you will make up for this over time in energy savings as well as bulb replacement costs.
  • Use for planted aquariums: Another primary weakness is in the area of planted aquariums. Many LED light fixtures are only suited for low to medium lighting needs. That will do nicely for virtually all fish and for a number of plants. Kelvin ratings of 6500K to 7000K are best for most planted aquariums. For plants that have high light needs, however, you will have to search for good LED lighting options.

The LED field is rapidly expanding with new products. Most experts agree the future is bright for LEDs.