Well ,today I went to J&L and picked up the 13K Giesemann Megachrome 400W SE and I have to say after having them on for about 2 hours, I sure like them, just the right mix of white and blue, and man they are BRIGHT!:biggrin:

What kind of ballast? I have been debating those exact ones.

Hummm Interesting. That a possibility. Haven't tried those and I sure like the DE ones on Tom R's tank

J

Ya, I had the 250W DE HQI's on my last tank, and I needed new bulbs so I figured why not try them now with 400W SE.
And I am very impressed to say the least, I would say they are very simlar to the DE ones

HQI ( high output ? ) ballast

You're running 400w SE's on an HQI ballast? No wonder they are bright!!! The HQI actually overdrives the SE as HQI are deisgned to run DEs. The Giesemanns are often nice bulbs. I realy like the 250w 13,000K SEs, but they are an expensive bulb, and the Ushio and XM have higher PAR (if I remember correctly...I haven't been up on lighting lately).

Well, for your information, Giesemann bulbs are designed to run on high output HQI or electronic ballasts. HQI ballasts and DE bulbs are used together but, that is not there only application, this is a common misconception.

kind of but not quite, the 250 watt HQI ballasts are a proper imitation of a greman power supply which will let you run all german based bulbs properly, actualy increasing life and output. The problem comes into play when we start talking about 400 watt HQI. there is no such thing. the balasts sold as 400 watt HQI are actualy HPS ballast which do overdrive the bulbs and shorten life. But having said that electronic ballasts have changed this a little allowing 400 watt bulbs to be run at a little higher power than the old mag ballast, with out as much impact on the bulb life but there still is some.

I have been complaining about places selling 400 watt HQI for about 6 years but it is a catch phrase to sell a product and while it is used corectly in 250 watt it isn't in 400 watt.

Oh and in my opinion the best bulb on the market is the AB 10K 250 watt SE, when driven by a 250 watt HQI ballast it gave me a life span of almost 2 years with only a 15% drop in output over that period, and produced higher PAR numbers than a 400 watt Iwasaki 6500K. problem is they are about 180.00 and hard to get in Canada.

Steve