Aquarium Blue Light – What Are The Benefits?

Aquarium lighting, and in particular the blue light is much more significant than people are led to believe, providing more benefit than simply aesthetics. By using an aquarium blue light you are mimicking moonlight, which modestly lights up your aquarium and encourages activity from your fish, invertebrates, and even plants. Additionally, aquarium blue lighting will not create algae growth spikes, nor will it negatively affect the day and night cycle of your fish.

Aquarium blue light

Your fish need suitable tank lighting as it promotes their growth and overall health. However, the most popular are certainly blue lights, so, let's find out why so many hobbyists opt for this color over the rest!

What Does Blue Light Do In An Aquarium?

The impact that aquarium lighting has on fish and other tank inhabitants is truly remarkable, enhancing metabolism and encouraging the growth of fish, making them strong and healthy.

Aquarium Blue Light for Plants

It tremendously helps out with regulating and providing structure to the eating and sleeping habits of fish, whilst providing oxygen too. In addition to these benefits, if you have live plants in a planted aquarium, the lighting will certainly provide much-needed nutrients for them and also corals.

For most living organisms, photosynthesis is crucial, and the same applies to fish and other aquarium inhabitants. The visible light spectrum consists of a multitude of different colors, with almost none of them having the same benefit as blue light when it comes to photosynthesizing.

Plants take to blue light incredibly well, stimulating the growth of strong, healthy leaves, and stems. Not only this, but it helps with plant pigmentation. For example, if you have red plants, the blue light will encourage their color to be fuller and brighter over time, the same applies to green plants too. This is all down to the correct nutrients being provided by the light.

Blue Light Aquarium Impact on Fish

Experts believe that the blue spectrum is one of, if not, the most essential color for both planted freshwater and saltwater reef aquariums. The blue light will illuminate your aquarium, mimicking moonlight, which helps indicate to fish the passage between dawn and dusk as if they were in the wild. The light will also calm fish down, and help some of the more nocturnal inhabitants become more active during the night.

Aquarium blue light

The nocturnal fish benefit tremendously from the dim blue light during the night when they are awake, whilst the diurnal fish enjoy it as it allows them to properly rest during the night. The aquarium blue light will encourage much more physical activity from fish whilst making it much easier for you to spot any potential health problems with them during times of activity.

Aquarium Blue Light Algae

Fortunately, unlike a lot of other lighting, blue light does not contribute to uncontrollable algae breakouts and growth, which are typically harmful to your fish and aquarium community. Usually, aquarium lighting will lead to increased water temperature, but this is not the case with blue lighting.

It is well-known that the water quality, as well as lighting, helps to encourage the bright and beautiful colors out of fish, and, blue light, in particular, will help to stimulate red, green, and blue colorations.

Can Fish Sleep in Blue Light?

Yes, they can. Due to the nature of blue lights in aquariums, replicating the moonlight from a fish's natural habitat in their captivity setting, they certainly can sleep and sleep even better than without a blue light! The blue light will not affect the day and night cycle of your fish, and neither will it negatively affect your plants.

Ambient blue is undoubtedly the best choice when it comes to your aquarium light, it allows your fish to sleep peacefully and calmly when the light is on. The light will help your nocturnal fish too, as they are not left in total darkness, but the lighting mimics the light they naturally roam around in when they're in the wild.

Blue LED Lights for Aquarium or Bulbs?

There is an abundance of brilliant options when it comes to aquarium lighting, but there is one that stands out from the rest, especially when it comes to providing a light that will benefit your entire fish community in terms of growth and coloration, and that is LED lighting. LED lights are typically more expensive than the other options, but you will certainly save time and money in the long run.

LED lights are much better for your aquarium than standard bulbs and metal halide lighting. Bulbs will generate a lot of heat, which will quickly increase your water temperature, forcing you to complete more frequent water changes to avoid your fish becoming unwell and stressed out. Additionally, warm water will promote algae outbreaks, which you certainly do not want.

The great thing about LED lights is that they do not raise the temperature of your water due to their low heat output. They also help illuminate the tank much more than standard bulbs with brilliant features such as adjustable light intensity. Also, on some models, the brightness can be adjusted via a timer too, to make the tank lighter and darker during selected times of the day. LEDs consume much less energy, reducing electrical costs and they also last much longer than traditional lighting.

Which is the Best LED Light Color?

One of the most popular LED light color for hobbyists is white, however, white is certainly not the best color to go for. White bulbs are incredibly bright and hard to adjust to for your fish, they also don't promote productive plant growth the same way blue lights and even green or red lights do.

Aquarium blue light

The calming effect of blue LED aquarium lights on your fish and plants is so beneficial to keeping a happy and healthy aquarium. You'll also probably find it very calming for yourself!

If you own a shallow tank, a red LED light is not a bad choice either as it helps out your plants due to red being easily absorbed by the water. However, overall, an aquarium blue light is your best option as it will not have a negative effect on any of your inhabitants, but if you do not like the color, then the next two to choose from would be green or red.


Aquarium blue lights are becoming more and more popular amongst hobbyists, and for good reason too! The benefits are tremendous for your tank, fish, and plants, with the addition of preventing algae breakouts. They help imitate the same natural environment your fish are used to, which helps them feel calm and happy.