As ever the sceptic in me says that can't be done. My opinion only that can easily be proven wrong. :D

I was under the impression that giesmen was using AB bulb and those Aqualine are manufacture by I dont know who

but BLV light bulb made by BLV Licht-und Vakuumtechnik GmbH it is a germany corp. wholly owned of the Japanese group USHIO Inc., Tokyo.

BLV product are sold in US and Canada under the name of ushio

A lot of people in Europe that I know use those BLV 10k cause they are able to get them cheap direct from the compagny and they are a real bargin. There life span on the other hand from those people are report to be not more than twelve month and even a lot report to change them 7-8
month cause they came realy yellow

For those who speak french or have a traduction software here is a
tread were they talk about life span of BLV

http://www.reef-guardian.com/modules...=2859#pid17733


here is a spectral analisis of the 10k BLV from 70 to 1000 watt in mogul or DD

http://www.blv.co.uk/spectrum_10k.gif

Again, it's difficult to conclude if a bulb is good or not if the comparaison is based under variable burning condition. As an image, you can fill your Honda Civic with super and still be unable to reach the performance of a Civic Si filled with regular engine being different.

Ballast as a lot to do with how a bulb (Of any manufacturers) will react when burned to their full intensity. A lighting fixtures is a complete unit and the material contained in it as a lot to do with the researched final results. Not to mention, the quality of the assembly that can play a role as well. The reflector play role (not in the spectrum indeed) and the UV filtering glass also.

Refering to the thread you posted now. I dont know about Arcadia fixture and with what ballast their are driven. Question is: would you change your bulbs each and every 6 month to have a perfect aesthetic result on your tank if it would cost you 40 box? Again, depend on your need and objective. In that same thread, someone even saying he's using 5200k (daylight) to obtain a coral growth explosion!!! everyone have an opinion and the prefect setup can be variable.

I've been kind of reading this thread and well one can argue astetics for ever. So really a waste of time.

Of coarse housing, bulb and ballast design play a role in the amount and intensity of light reaching the desired area. What we as consumers need are numbers. Seeing we have a rep in the thread why don't we get those and while that is happening let the hobbiest debate opinions.