How Does the Color of Light Affect Fish?

Answer

• The color of light does not have a significant impact on fish. Many species of fish, including most goldfish, are able to see in color. Fish that are exposed to monochromatic light from a colored light bulb will not show any serious signs of harm or confusion. However, the intensity of light and length of time that they are exposed to light can affect aquarium fish.

Intensity of Light

• The intensity, or brightness, of light can affect fish, regardless of the color of light. As stated earlier, many aquarium fish can see in color, but their vision is not excellent. Exposure to very bright light can harm certain species over time, particularly species that like to hide in dark corners of the tank and under rocks. Soft light, even if it colored light, is always preferable to any type of intense lighting in a fish tank.

Duration of Exposure

• The length of time that fish are exposed to light can also affect fish, again regardless of the color of the light. Aquarium fish treat their tank just like it is their natural habit, so their bodies adjust to all of the surroundings, including the lighting. Fish need a regular pattern of exposure of a light source and withdrawal from that light source. This means that ideally, you should turn the tank light off during the day and turn it on at night. Your fish will adjust to this pattern as they swim around in their aquatic home.

Ideal Aquarium Lighting

• Fish prefer lighting that most closely mimics the natural sunlight that they would receive in the wild. Soft, white light from a fluorescent light bulb is common in most fish tanks. You could perhaps use a colored light bulb, but if you do, stick with "cool" colors, such as blue or blue-green.