Lighting has always been a matter of consideration for aquarium enthusiasts, both hobbyists and professionals. As a general rule, regular lights used in the household are not used for fish or reef aquariums because they give off too much heat, eat up a lot of energy, and do not bring out the colors of corals and fishes
Instead, metal halide bulbs became a much popular and convenient choice. Metal halide bulbs gives off high-intensity light coming from mercury's radiation. But instead of giving off white light, the light has a bluish tint, which is the hue deemed best for fishes and corals. For metal halide bulbs, a high Kelvin rating, denoted by K, means a bluer tint. To give you a point of reference, a rating of 10,000 K is equivalent to white light. The higher you go than 10,000K, the bluer the light gets.
The 150-Watt 20,000K+ Metal Halide Bulb - Ushio, Double-Ended from Pet Store
has a high Kelvin rating, which means that the light it gives off is perceivably blue. This hue brings out the vivid colors of fishes and corals, which makes it an ideal lighting choice for many people.The 150-Watt 20,000K+ Metal Halide Bulb - Ushio, Double-Ended gives off high heat because of the strong intensity of the light it gives off. Thus, it comes with a handy ultraviolet shield to lessen the UV rays reaching the tank without decreasing the light intensity.
At 150 watts, this metal halide bulb uses up a small amount of energy so you can leave it on continuously so you can enjoy looking at the beauty of your aquarium.
We offer a wide variety of Metal Halide bulb choices to suit your aquarium lighting needs.
A Metal Halide Lamp is a high-intensity discharge light source in which the light is produced by the radiation from mercury, plus halides of metals such as sodium, scandium, indium, and dysprosium. The K at the end of color rating for each bulb stands for Kelvin. This is a measurement of the color temperature. The higher the Kelvin rating, the cooler (bluer) the color of light given off by the bulb. In general, the color given off by the 10,000K German is interpreted as being a perfect white color.
There are two main considerations to decide upon when chosing Metal Halide bulbs and systems: wattage and color temperature.
- There are generally two considerations when planning wattage, tank depth and the requirements of various types of corals. Tanks 18" and shorter will, typically, use 175 or 250 watt MH bulbs. Typically, tanks 24" and over will use 400 watt MH bulbs. I have found most soft and large-polyped-stony corals to do just fine within 5-15 inches from a 175 watt bulb and 10-24 inches from a 400 watt bulb. Most small-polyped-stony corals survive within 5-10 inches from a 175 watt but appear to thrive within 5-15 inches of 250 and 400 watt bulbs. These are all just general statements to assist in going the correct route with chosing wattage. They are not absolute truths.
- Color temperature is a hotly debated topic where there is no one recommendation that will fit everybody. Lowers Kelvin temperatures are yellower and greener colors while higher Kelvin temperatures are whiter and bluer colors. There are two factors that determine most hobbysts choice of bulb colors, par rating and aesthetics. The 6500K Iwasaki bulb is generally regarded as an excellent PAR rated bulb. However, it`s green tinged yellowish color makes for what is considered by many as poor aesthetics. This is not the say the much bluer 20,000K German bulb is aesthetically ideal. Many hobbyists complain this bulb is too blue. By far, the bulbs most popularly purchased are the 10,000K German and the 12,000K Sunburst bulbs. The majority of hobbyists choose aesthetics as the determining factor of chosing color temperature for the primary reason that the appearance of our aquariums is of utmost importance. Due to the subjective nature of color preference, we refrain from making suggestions on which color temperature is right for you. Instead, we have a visual bulb comparison of the popular bulbs on the market.
As a general rule of thumb, use one metal halide bulb for 24" of tank length. Most of the Metal Halide bulbs in the same wattage format can be interchanged. However, please contact us to make sure. Metal Halide bulbs are one the most difficult aspects of the hobby to recommend. Most of the information here is general.
Common questions/problems concerning metal halide lamps:
- Metal halide lamps of the same kind are different colors?
Metal halide lamps operate by passing an electric arc through an arc tube that excites particles in the arc tube. When the metal particles reach an excited state they emit energy in the form of visible light. It takes 100 hours of operation before the metal particles stabilize and become a consistent color. All metal halides require 100 hours of operation before color and light output stabilize. All metal halides inherently have a slight color variation between individual lamps.
- The metal halide lamp fires and then either burns dull or the arc extinguishes?
Usually the ballast and lamp are not receiving enough power. Metal halides pull a high current. Usually the problem is either there is too great a load on the circuit or the extension cords are of a small wire size and can`t handle the power needed by the ballast. Use only heavy duty extension cords and try running a ballast off a circuit from another part of the house.
- Do I need a cover shield