Aquarium Blue Light: All You Need to Know About

LEDs inside the aquarium add a unique flair for ambience and appearance. But there’s more to it as such lighting benefits the inhabitants inside by keeping the environment healthy.

The aquarium blue light acts as the perfect alternative to the moonlight. It encourages the physical activity of the fish inside. Also, it creates a shimmer effect, which eventually produces a superb underwater ambience like that of the ocean bed at night.

That said, blue lights are widely used inside the aquarium for superior benefits. This article will explain the reason behind the usage and cover other essential aspects. So, without wasting any moment, let us find out.

Overview of the Aquarium Blue Light

Lighting inside the aquarium does have a significant impact on the inhabitants and the environment inside. It enhances the metabolism and also the growth of the organisms inside. That said, it is also the same aquarium blue LED lights.

What Is Aquarium Blue Light?

What Is Aquarium Blue Light

You can use different lighting spectrums inside an aquarium. When the blue spectrum is dominant, the lighting inside is blue LED focused.

It is one of the most common lighting spectrums by aquarium owners. They are even called the moonlight light as one of their main focuses is monitoring nocturnal fishes at night.

Why Use Aquarium Blue Light?

There is no better option than blue LEDs to mimic the ambience of the natural moonlit inside an aquarium. It illuminates the light so that the fishes hardly feel that they are getting artificial lighting.

Why Use Aquarium Blue Light

These LED lights ripple effect on the fish tank bed, eventually generating the seabed vibe at night.

Blue LED lights are also beneficial for the inhabitants and the aquatic plants inside. Mainly, if you have coral inside, the blue light will be the best option for its development. In addition, the blue light makes it easy for the plants to do photosynthesis.

Using blue LED aquarium lights ensures that the physical activity of the fish increases. And that means that this lighting spectrum focuses on creating a natural environment.

Is Blue Light Safe or Harmful?

The blue lighting in the aquarium won’t harm the fish and plants inside if used correctly. Unlike most other lighting spectrums, the blue lights don’t increase the water temperature. It reduces the need to monitor the water temperature.

But excessive blue lighting might hurt the fish’s reproductive cycle. That is why it is better to try out the blue LED lights than the other options.

How Much Blue Lighting Is Enough for The Aquarium?

Since excessive blue lighting may affect the fish’s reproductive ability, it must be on a tolerant level. Primarily, every activity of the fish is somewhat regulated by the lighting.

That said, the time frame for the blue lighting should be somewhere around 8-10 hours. Anything more than this would be considered harmful and gradually hurt the fish tank environment.

Good Sides

  • Blue light doesn’t contribute to the algae growth
  • Ensures proper transition between dusk and dawn
  • It helps in enhancing the physical movement of fishes
  • Assists in the growth of aquatic plants
  • Enables monitoring of fish activity and health


  • Too much lighting might affect the fish’s reproductive cycle

How To Set Aquarium Blue Light In A Fish Tank?

Blue LED lights in the aquarium will make the fish feel its natural habitat if set correctly. To set the blue light, you must first decide the number of lights and gather the required tools.

Some of the most prominent materials and tools are – Roll of Blue LED strips, Plastic rain gutter, End caps, Hacksaw, Drill, Electrical tape etc.

Here are the steps to install the blue LEDs in a fish tank:

Step-1: Test the LEDs

Pull out the roll of the LED strip and then connect it to the adapter. After doing so, connect it to the power supply and check whether the strips are in working condition.

Test the LEDs To Set Aquarium Blue Light In A Fish Tank

Step-2: Cut The Rain Gutter To Prepare Housing

With the hacksaw, cut the plastic rain gutter. While cutting, you should ensure that the cut’s length is a couple of inches shorter than the length of the tank. It is needed to provide end caps with a bit of room.

Cut The Rain Gutter To Prepare Housing

Step-3: Drill One Of The End Caps

Use a drill machine to make a hole in the end caps. It is mainly for allowing the LED strips to pass through the length of the gutter. Here is a tip, first make three holes then add them up, it will make the housing nice and spacious.

Drill One Of The End Caps

Step-4: Attach End Caps

Place the end caps on both the ends of the gutter very firmly. Make sure they are placed perfectly.

Attach End Caps

Step-5: Pass the LED strips

Pass the LED strips after connecting with the power supply through the end caps and check the length.

Pass the LED strips

Step-6: Cut the Strips

You may find the leds longer than the desired size, in that case, cut these to fit the aquarium size perfectly. For that, use a scissor to cut the strips by the length of the plastic gutter.

Cut the Strips

Step-7: Place the LED strips

Use the electrical tape to attach the LED strips to the plastic gutter and ensure the placement.

Place the LED strips

Step-8: Place the Gutter

Attach the gutter or gutters on the fish tank and then check the connection.

Place the gutter

Can You Leave Blue Light on In the Fish Tank?

The idea of leaving the light on in the fish tank 24/7 can harm fish. It isn’t a good practice because the lights will affect the sleeping pattern of the fishes.

That said, the sleeping pattern of the fishes has a considerable impact on their overall activities. Their behavior and habits are primarily dictated depending on how much they sleep. For this reason, you must not keep the lights on all the time; it doesn’t matter what the spectrum is.

Blue lights in aquariums might give good outcomes. But since most fishes are diurnal, it is better to leave the blue light off at night. As a result, they can sleep and have a healthy sleep cycle.

Do Blue Aquarium Lights Cause Algae?

No, the blue aquarium lights won’t cause algae single-handedly. The main reason for algae formation has light as one of its components. But it’s not the main reason as light, carbon-di-oxide, fertilizer etc.; everything plays a part.

With the blue aquarium LED lights, it is safe to say that they will not cause algae formation. If the intensity of the light is at controlled levels, you can always avoid the algae formation risk.

Aquarium Blue Light Maintenance Guide

With the blue lights in the fish tank, you need to ensure that these LEDs are taken care of. Some of the critical aspects of their maintenance are discussed below:

  • Clean Mineral Deposits: The salt or lime depositing on the LEDs can result in damaging them. That is why you should always clean the LED strips and don’t let the mineral deposits settle on them.
  • Ventilation: Ensure that the LED lights have enough ventilation scope. Since these lights will be illuminating, the LEDs will produce heat. It would be necessary to make this heat pass out, or the lights’ lifespan will drop drastically.


The benefits of using blue LED lights on the aquarium outweigh its drawbacks. Using these LEDs enables the inhabitants’ growth and enhances aquatic plant growth.

Installing such lights in a fish tank makes it more habitable for the fish. All these LEDs should be set so that it doesn’t affect the condition much with no implications.

Moreover, we hope that this article has made everything clear about the blue aquarium lighting. Still, if anything seems confusing, do let us know.

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