Aquarium Light Vs. Grow Light [Differences You Should Know]

Aquarium Light Vs. Grow Light [Differences You Should Know]

Image of an aquarium with grow lights

Aquarium lights are usually used for illuminating the aquarium and viewing the activities of the tank inhabitants. On the other hand, grow lights are used to promote plant growth. Grow lights consist of high-intensity lamps that emit lights with specific wavelengths for the faster growth of plants.

Although aquarium lights and grow lights seem similar, both have a specific use that sets them apart.

Aquarium Light Vs. Grow Light – Main Differences

Following are the main differences between aquarium lights and grow lights.

Plant Growth Suitability

The most notable difference between an aquarium light and a grow light is that while a grow light is designed to help plants grow faster, an aquarium light is designed to illuminate the aquarium.

Not all aquarium lights are suitable for plant growth as some may emit high heat while others may lack the correct light spectrum for the optimal growth of plants.

In contrast, grow lights are specially designed to deliver specific wavelengths of light that plants need for maximum growth.


LED grow lights typically consist of several individual LEDs mounted within a casing with a heat sink and a fan assembly.

Most LED grow lights don’t need any special ballasts and can be plugged into a standard electric socket.

On the contrary, aquarium lights don’t have these features.

Color Spectrum

Another noticeable difference between an aquarium light and a grow light is the color spectrum.

Aquarium lights have more green and less red and blue colors that give the aquarium an appealing look.

Also, aquarium lights produce a bright white light that helps to show off the colors of fish.

On the other hand, grow lights have a more red and blue light that enhances plant growth.

Kelvin Rating

Kelvin Rating is another primary difference between aquarium lights and grow lights.

Kelvin in lights refers to the measurement used to describe the color of the light source.

It describes the coolness or warmth of the light source.

Aquarium lights have a high Kelvin Rating of 8000K and above, producing a bright white to blue color spectrum.

On the other hand, grow lights usually have a Kelvin Rating between 4700K to 6700K.

They emit a pinkish-white light that emulates the natural daylight and is also ideal for the photosynthesis process.

Types Of Aquarium Lights

Light is necessary for sustaining life inside an aquarium, be it of aquatic creatures or plants. Without adequate lighting, fish growth gets stunted.

Besides, inadequate lighting also adversely affects fish pigmentation.

So, let’s understand the different types of aquarium lights.

LED Lights

LED lights are popular for aquarium use due to their low power consumption and long lifespan.

Besides, they don’t emit much heat like other aquarium lights. This helps to keep the tank water temperature stable.

The most common type of LED light used in aquariums is strip lights. These strips have a variety of colors.

They come with an adjustable mounting bracket so that you can mount them on your tank wall.

Another advantage of LED lights is that you can adjust the light intensity as per the aquarium requirement.

Standard Fluorescent Lights

Standard fluorescent lights are most commonly used in aquariums.

This is because they are pretty inexpensive and are energy efficient.

Also, they come in numerous colors and various sizes. So they easily fit in any aquarium hood.

These lights are mainly used in non-planted tanks.

They are not suitable for planted tanks as these bulbs don’t produce the high-intensity light that plants need for optimal growth.

Compact Fluorescent Lights

Compact fluorescent lights give high output than standard fluorescent lights.

They are energy-efficient and hence are a great alternative to standard fluorescent lights.

Although these bulbs are smaller, they create more illumination than the standard fluorescent bulbs.

Moreover, you can use them in fish and planted aquariums as they come in various wattages.

The only drawback of these bulbs is that they emit some heat.

So you need to invest in an auxiliary fan to prevent the tank from overheating.

Metal Halides

Metal halides are powerful aquarium lights.

They produce high-intensity light and are often used for reef tanks where the tank inhabitants need high light intensity to thrive.

Moreover, they are also used in large and deep tanks as they penetrate water up to 20 inches deep.

The only disadvantage of these lights is that they emit a lot of heat and are comparatively expensive than other aquarium lights.

Incandescent Lights

Incandescent lights were initially used in aquariums.

However, now they have become obsolete. Aquarists don’t prefer these lights as they emit a lot of heat.

Although incandescent lights are less expensive compared to other aquarium lights, they are less efficient.

Also, these lights need frequent replacement, and so they increase the overall cost.

Types Of Grow Lights

Grow lights are specifically designed to provide sufficient light for plant growth at various stages.

They enhance plant growth within an aquarium.

So let’s see the different types of grow lights.

HID (High-Intensity Discharge) Lights

HID lights include high-pressure sodium lights and metal halide lights.

They are very high-intensity lights and are mainly used in coral reef tanks.

HID lights are also used in very deep and large tanks. Since these lights are very powerful, they emit a lot of heat.

So you will need extraction equipment to remove the hot air.

T5 HO (High Output) Fluorescent Lights

T5 HO fluorescent tubes are popular grow lights that are widely used in planted aquariums.

They are reasonably inexpensive and long-lasting.

Besides, these lights are conducive for aquarium plant growth as they produce high-intensity light.

Also, they emit less heat than metal halide lights, so there is no need for an additional cooling system.

LED Grow Lights

LED grow lights are considered environmentally friendly. They consume less electricity and hence last longer than traditional lamps.

LED grow lights provide a light spectrum similar to sun rays. So they boost the growth of aquarium plants.

Moreover, they are available in different shapes and sizes and are tailor-made for most aquarium setups.

Can Aquarium Lights Be Used As Grow Lights?

Grow lights are specifically used for growing plants. They have a specific wavelength that helps in photosynthesis.

Grow lights can be customized to emit light within specific wavelengths, colors, and lumens to match the needs of different plants.

LED aquarium lights can be used as grow lights, provided they emit enough light intensity for plants to grow optimally.

Plants primarily absorb red and blue light for growth.

Grow lights have a balanced spectral output of blue and red wavelength that stimulates plant growth.

The LED aquarium lights that provide the same light intensity and wavelength can be effectively used to grow plants in aquariums.

Can Grow Lights Be Used For Other Purposes?

Grow lights are designed for a specific purpose to help in different phases of plant growth.

The primary purpose of using grow lights in planted aquariums is to reduce the cost of lighting while growing plants with minimum natural light.

Grow lights can also use lights to monitor what’s happening inside the tank.

However, aquarists often don’t prefer grow lights for a non-planted tank as numerous aquarium lights are readily available that provide a sufficient amount of light for fish.

Moreover, such lights also enhance the aquarium’s beauty with their varied colors.

Do LED Grow Lights Affect Fish And Plants?

LED grow lights don’t affect the fish.

On the contrary, they are beneficial to fish as these lights emit blue light, which is soothing to fish.

Another advantage of LED grow lights is that they emit less heat.

So the generated heat doesn’t alter the tank water temperature nor stresses the fish.

Apart from being beneficial to fish, LED grow lights are suitable for plants as well. They are used to stimulate plant growth.

These lights are usually placed above or below the plants. The light emitted by these lights helps plants to grow fast and healthy.

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