why are there different color light bulbs for aquariums?

Question

is it just for looks or is there an actual purpose to them? i was looking for bulbs and found that there were green, blue, and clear glass bulbs as well as one that sort of looked like white with a little blue tint to it. do these lights function in any special way and if so what way?

Answer 1

In the screw-in incandescent bulbs it's just for decoration. I've even seen questions on here from people asking about using food coloring to make their tank look different colors (and the lights are a safer option for your fish). The different colors only work for tanks with just fish - they don't allow plants to grow well.

In fluorescent tube, the different colors do serve a purpose. If you look at the specifications on the packaging, many of these will have a kelvin rating (some number and a K). While this technically refers to the "hotness" of which something burns (as in when it's used to determine the color of stars by how hot they burn), in fishkeeping it's more synonomous with the color of light under natural sunlight or at varying depths of water where certain wavelengths of light are filtered out by the water. The deeper you go, the more "blue" the light becomes. These are mostly used for marine tanks. A rating of 5500K simulates natural sunlight at the surface, but the light has a yellow cast (our sun is considered a "yellow" star). As the number gets lower, it becomes more orange-red. As the number goes up, it goes through white to blue, to ultraviolet. To remove some of the "yellow", tubes generally are in the 6000-8000K range which is a "whiter" light. Reef tanks use 10,000K to simulate lighting at a depth of about 30 feet of water, where corals would live, and has a light blue tint. A deeper blue (03 actinic) simulates dawn and dusk lighting, and is important to trigger reproduction in some corals.

And yes, the different colors of lamps/tubes can be used to enhance the colors of certain fish.

Plant bulbs tend to be a more purple color, since plants use more light in those wavelengths for photosynthesis.

Answer 2

Some aquarium plants need bluer light that is more like day light. I think the colored incandescent lights are usually just decorative though.

Answer 3

will in most fresh water tank no but if u have a salt water or reff tank u need the bule light for thing to grown. i have a 95w 1000k and a 95w bule linght on my 50 gal tank . but for fresh water i think they are just 4 looks

Answer 4

Certain lights bring out certain colors in certain fish