Blue Light For Fish

Many aquariums have blue LED lighting systems usually turned on at night.

The eerie blue environment makes the aquarium look otherworldly to the human eyes, a common reason for the enduring popularity of blue lighting.

But it’s crucial to look beyond the aesthetics of blue light!

Do fish like blue light at night? They do! Blue LED lighting can mark the transition between dawn and dusk and mimic moonlight. Don’t worry about ambient blue light affecting your fish’s night-and-day cycle and the growth of plants, corals, and algae.

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Read on to find out more about blue lights for the aquarium.

We will discuss the advantages of LED lighting and the number of hours that LED lighting should be turned on and off.

Choose LED Lighting When Possible

While standard fluorescent bulbs, metal halide lights, and compact fluorescent bulbs are good options for aquarium lighting, these have more cons than pros.

LED lights, such as the AQUANEAT LED Aquarium Light, are highly recommended because of their low heat output.

These lights will not increase the water temperature in the aquarium yet will continue to provide light for your fish.

Nocturnal fish mainly prefer dim blue lighting at night.

The blue lights mimic moonlight and, thus, encourage more physical activity, providing them with illumination.

There’s also that blue light that allows you, their human parent, to view them well.

LED lights can also be adjusted for light intensity.

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These can be programmed to be brighter or dimmer depending on the time of day, mainly via a timer.

This feature also means lower energy consumption, not to mention that LED lights consume 80% less electricity.

White and blue are the most common colors on an LED lighting system.

But did you know that these also come in a rainbow of colors?

A magenta LED light system will encourage photosynthesis in plants while also enhancing the tank’s blues, reds, and greens.

Consider the Tank Conditions

The number of hours the blue LED lights are on at night is also crucial for the fish’s health and overall condition.

After turning off the tank’s leading lights, you can run the lights for about two hours in a freshwater tank. In the case of a saltwater tank, you may run the blue and white lights for a more extended period.

But it would help if you also considered the specific needs of your fish were lights on and off are concerned.

Remember that most fish species require sufficient hours of complete darkness to sleep.

The number of hours the blue lights are kept on should be within the recommended 12-hour daytime-like conditions.

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For example, turn the lights on for 12 hours during the day and then turn them off for 12 hours at night if your fish are diurnal.

You can reverse the cycle in the case of nocturnal fish.

You may turn on the blue lights for two hours within the 12-hour daytime hours, preferably as dusk nears.


Fish have their specific lighting needs for their proper growth and development. Your job is to know what type of light they need, their hours, and their effect on their body.

If possible, you will want blue lights for them at certain early evening hours.