Sanjay Life-testing of 400W SE MH Lamps

[andy]

Very interesting reading at Advanced Aquarist:

Feature Article: Metal Halide Lamps - Aging Over Time: XM, EVC and Giesmann Coral 400W Mogul Lamps

 

Interesting points:

 

• Bulbs run on magnetic ballasts actually increase PPFD output over time
  
• Bulbs lose their blues first
  
• The Penn State tanks run a 12-hour photoperiod
  
• Sanjay replaces his personal bulbs every 15 months
  
• Implication: If you can deal with the color shift, you can run bulbs for a lot longer than 12 months.