Item Code: 23-5000947

* Made in Germany!
* The Ushio 20,000K has a nice blue tint to it.
* A great bulb for the cost conscious aquarist who wants to add blue without adding additional Actinic lighting.
* Mogul base.
* ANSI Standard: M59

FAQ:
Q. What are the ANSI codes for Probe Start and Pulse Start ballasts?
A. Probe Start ANSI Codes for Metal Halide lamps: M102=150W, M57=175W, M58=250W, M59=400W, M47=1,000W.
Pulse Start ANSI Codes for Metal Halide lamps: M85=70W HQI, M81=150W HQI, M137=175W, M138=250W, M135=400W.
Q. What is the deal with "pulse start" or "probe start" ballasts?
A. "Probe start" ballasts are more common in the U.S., while "pulse start" ballasts are more common overseas. Most aquarium lighting hoods and pendants sold here in the US have PROBE start ballasts, as most MH lamps sold here are made for those ballasts. However, the short list of PULSE start style lamps commonly sold in the aquarium trade would be: 175W and 400W Ushio 10,000K, and both 250W and 400W Radium 20,000Ks. Those lamps will generally operate fine on pulse start ballasts, and we see little to no problems. We sell both pulse and probe start ballasts so you can get the correct one for your lighting needs.
Q. Why do 20,000K bulb all have different colors? Shouldn't they all be the same if they're marked "20,000K"??
A. Color Temperature ratings (i.e. "K") is more of a marketing term than a true scientific measurement for color. There are far too many variables when it comes to an accurate "K" rating. Bulbs of the same manufacture can color up differently over time, as the ballast ages (although this is generally not noticeable by the aquarist). This is why most "K" is used as a reference rather than an absolute. The higher the K, generally the more "blue" the bulb becomes. Sunlight is about 5,500K.
Q. All these color temperatures seem confusing. Which one should I go with?
A. Always ask yourself what's most important to you and your tank specimens. If you are an SPS keeper, and your goal is growth, then we suggest 250W or 400W Iwasaki 6,500K bulbs. If you have lower light corals and want a "deep water" look, then go with a 20,000K bulb. If you want "crisp white", then go with a Ushio 10,000K. Just remember that any new bulb that you have never tried will look different to you, as you've grown accustomed to the previous type. Visual color is a matter of personal preference.