What Is The Purpose Of A Light In A Fish Tank?

Freshwater aquarium lighting is very important in a freshwater tank. It serves many functions both to man, lower animals and plants. It is the reason you can see the person standing next to you and plants are able to produce their own food. This importance of light also spreads to the ‘fish tank’.

Light in a fish tank serves three main functions:

  • Aesthetic: The beauty of your fish tank is not only due to the type of the fishes in it but also on how lit up the tank is. Light helps to make the colours of the fishes in your tank appear more beautiful by shining on them and in return their skin reflecting this light to your eyes. Your tank also looks better when lit up. Special colour-enhancing bulbs are available, that helps you maximize the colour of your aquarium fish.
  • Photosynthesis: Aquarium lightening helps to provide energy for the live plants which may be in your tank. Living plants through the process of photosynthesis converts light into glucose (energy) in the presence of chlorophyll and carbon dioxide into oxygen. Since plants utilise light as an energy source, it’s important to make sure that your aquarium lighting system is good.
  • It prevents tropical fish from sleeping during the day: Imagine how fish tanks will look, if all the fishes which are supposed to be beautifying the tank, decide to take an afternoon nap, I guess it will look really bad. This makes lightning up your tank very important. Light helps to prevent animals from sleeping by preventing the release of the sleeping hormone from their brain, and since fishes are also animals, it serves this function also in them.

Now that you know how important it is to have light in a fish tank, let’s now look at the type of fluorescent bulbs to use in a fish tank.

Many types of aquarium lighting systems are currently available, and in order to understand the differences, you should be familiar with a few terms.

Fluorescent bulbs emit light rays at different wavelengths, from different parts of the light spectrum.

Below is an overview of the most common types of aquarium lightning:

    • Power Compact; Power compact bulbs have a similar lumen-per-watt rating as T-5 bulbs, which is about 60 lumens per watt. These high-powered bulbs come in three different varieties: straight-pin, square-pin and a self-ballasted screw-in variety. These bulbs are commonly used in aquariums.
    • Actinic; at the blue end of the colour spectrum, you will find actinic light. This type of light penetrates deep water better than white light; this makes actinic light the light of choice for large saltwater tanks. Actinic bulbs emit a combination of blue and white light.
    • Colour-Enhancing; actinic or daylight bulbs may either be colour-enhancing or not. The colour-enhancing types are designed to enrich the natural colouration of aquarium fish. They put out the light from the warmer end of the spectrum and can be used for either freshwater or saltwater tanks.
    • Fluorescent; one of the most common bulbs utilized by aquarium lighting systems is the Fluorescent bulb. This bulb comes in different forms, but the most common are the standard fluorescent, compact fluorescent, T-5 HO and VHO bulbs. It functions as a gas-discharge lamp, which uses electricity to excite the mercury vapours contained within the bulb to produce light. The different wattages and intensities of light produced by fluorescent bulbs vary based on the type.
    • Incandescent; in this type of bulb, light is produced when the electricity heats up the filament wire contained within the bulb, causing it to glow thereby producing light. Incandescent bulbs should not be your bulb of choice for an aquarium as they produce too much heat.
    • LED; this is probably the most common type of light. It is a light-emitting diode and not really light bulbs. It saves power and is very durable. These light-emitting diodes produce a unique effect when used. By doing so, they enhance the appearance of the fish tank, making it look more beautiful. This source of light is useful in creating an effect which is beneficial to nocturnal tank inhabitants.
    • Full-Spectrum; bulbs in this category emit light from all visible wavelengths. These bulbs are sometimes called daylight bulbs because the light they emit is similar to that of daylight; they make good lighting for aquariums.
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The type of lightening system you should use in your tank should be decided based on the type of tank you have and its use:

In freshwater aquariums, there are two main types of the tank;

  • Fish-only tanks.
  • Planted aquariums.

As the name suggests, a fish-only tank only has fish bred in it, as such, it does not a lot of lightning is required. A planted aquarium, on the other hand, requires a lot more lighting because plants are photosynthetic organisms and so use light as an energy source.

A fish-only tank requires a lighting system that provides at least 1 or 2 watts per gallon of light. But a planted fish tank require between 2 to 5 watts per gallon of full-spectrum light in order to do well.

The size of your tank

For a small tank, only one source of light may be needed, but for a large tank, you may need several sources to ensure the even distribution of light.

Let’s say you ever get confused at any point on what type of aquarium lighting system would be right for you, don’t hesitate to ask a professional. But if you can’t get in touch with an expert, you can do your own research online, so you have a few brands or systems in mind before you head out to the pet store.

Installing the right lighting system in your aquarium is very important, so it is not a decision that should be made lightly. Make sure you understanding the basics of aquarium lightning, including some of the terms used to describe aquarium lighting before setting up one, as this is important if you wish to make the right choice.