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150 Watt 21000K Metal Halide Bulb - Megachrome Blue, Double Ended

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MB2815

This item has been discontinued.

Giesemann Aquaristic

We offer a wide variety of Metal Halide bulb choices to suit your aquarium lighting needs.

Most of the MH bulbs in the same wattage format can be interchanged. However, please contact us to make sure.

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.

NOTE: Double ended bulbs should always be used with the UV shield (supplied with most pendants). You and your corals can suffer from excess UV radiation otherwise. The bulb should be handled carefully as well since it has no outer glass casing. Using soft gloves is a good idea to keep finger prints off bulb. This is during installation and replacement.

Bulb Replacement Guide
Bulb Types Life of Bulb*
Normal Output Fluorescent 6-12 months
Very High Output (VHO) 6-12 months
Power Compact (PC) 9-12 months
T5 High Output (T5HO) 9-18 months
Metal Halide 9-12 months
LED (non-moonlight) ~5 years (50,000 hours)
* Manufacturer Recommendations


13 Reviews

ROBERT MORETTI from Saint Charles, IL UNITED STATE

10/24/2013

Experience Level: Expert

Worth every penny

This bulb was the first that I have purchased for my nano. I usually try to go with the cheaper bulbs which saved me maybe $20-$30 dollars. This bulb was a major difference immediately. I would strongly recommend this if you want a super bright bulb with great blue tint. Everything in my tank responded like never before to the intensity and color of this bulb.

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STEVE TORRES from PARADISE VALLEY, AZ UNITED STA

04/22/2013

Experience Level: Intermediate

Bad bulb

I bought two bulbs. The light being emitted from one bulb is yellow and the bulb is flickering. I was told by customer support to give it a couple of days to burn off the gasses. I may have to return it. It has been several days without change. The good bulb has a nice blue color.

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RANDY BURTON from CLAREMORE, OK UNITED STATES

01/07/2013

Experience Level: Expert

Outstanding! - worth the money

I have used numerous Halide bulbs during my years of salt water aquariums. These Geismann 20,000 bulbs are amazing!! Sure, they cost more than other bulbs but $36 more than a cheaper bulb is only $3.00 / month. I have used Ushio, XM, Hamilton and other bulbs. These make the others look sick. If you want your corals to POP, you will be very pleased. I combined three of these Halides with the Geisemann 39 Watt blue acntics (qty. of 4). Don't think you can have too much blue. Ver pleased with Geisemann bulbs and won't be buying any other brand..

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Florida girl from Gulf Coast, FL

02/22/2012

Experience Level: Intermediate

Great bulb

Bulb made an immediate difference over the off brand 14000k bulb I had been using. Corals which were browned out are now vibrant blues and greens. Tank looks awesome. It is expensive, but it's the best improvement for the money I've made to my tank. Highly recommend!

1 out of 1 found this review helpful

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JUSTIN BRUZDZINSKI from DUNDALK, MD UNITED STATES

08/07/2010

Experience Level: Intermediate

love it

I am extremely happy with this bulb. It has made huge difference in my tank with coral and acutely algae growth it has slowed algae down to where I can clean walls every few days and its still clear blue water...love the light would highly recommend

1 out of 1 found this review helpful

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RICHARD SCOVILL from SPRINGFIELD, OR UNITED STATES

05/10/2010

Experience Level: Expert

Great Color/Average Life Span

I love the color of these bulbs. They will give you nine months of great coloration and growth from your corals. However, my first pair shifted spectrum at nine months and needed to be replaced. 9-12 months is the expected life span of HQI bulbs. Despite the shorter life span I believe these bulbs are worth the extra money.

1 out of 1 found this review helpful

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ELVIN LAI from POWAY, CA UNITED STATES

06/29/2009

Experience Level: Expert

Dont Fit

bulbs did not fit my fixtures, and kept slipping out.

1 out of 13 found this review helpful

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TONY CHRISTENSEN from OGDEN, UT UNITED STATES

05/19/2009

Experience Level: Intermediate

20000K Metal Halide Bulb - Meg

I love these bulbs! My corals "pop" more than ever, they really bring out the colors. If your in the market for a good 20K light, this is it!

2 out of 2 found this review helpful

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apatheticmonkey from HOUSTON, TX UNITED STATES

07/22/2008

Experience Level: Intermediate

This bulb rocks!

As the title says . . THIS BULB ROCKS. I was originally hesitant to drop an extra $40 on this bulb but in actuallity that is the cheapest investment you can make to get your tank to shine like that. Over the past five years, I have tried both PFO and Metal Halide lighting with various bulbs and arrangements. None of which compare to the quality of light provided by this 250 W 20000K Metal Halide Bulb. The light is by far the most crisp and clear I have ever seen. My tank has really impressed made me smile in the past but I couldn't help but grin from ear to ear when I put this bulb in. (BTW it takes a few days for the bulb to get broken in and really shine)

2 out of 2 found this review helpful

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TONYA BEAM from CHANDLER, TX UNITED STATES

07/07/2008

Experience Level: Intermediate

megachrome 20K

I would highly recommend these light, they are great. If you want your coral colors to pop Buy these lights. I had 10K's and they were fine but I wanted more blue, so I ordered the 20k megachrome and I was so pleased. Plus my coral love them. One thing I have to say also, I have ordered from Marine Depot several times and they always have good prices and if you need help just call they are always helpful and have some one who can answer any question you may have about a product. Hope this helps someone who may be wondering about the 20k's. Thanks Tonya Beam

3 out of 3 found this review helpful

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