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.
__________________
Truth lies in the eyes of the looking one! 
|