When to change MH lamps?

[jgagel]

How long do you wait between you change your MH bulbs? What is recommended? What is too long?

 

[liquid]

It depends on the color temperature of the bulb. The higher in kelvin you go, the sooner you need to change out the bulb. FWIW, my Iwasaki's (6500K)last me 12-18 months w/ no problems.

Shane

 

[Anonymous]

Except for the radiums I have heard that the standard time between changes is 12 months. The raduims need to be changed every 6 months.

 

[ChrisRD]

I think that's a very tough question to answer because it really depends on what lamp you're talking about, what ballast you're running it on, how long it's on each day, how hot it's getting (ventilation), etc.

FWIW I've been running one of my DE lamps for about 18 months now and it still looks good (using the lamp next to it for reference, which is less than 1 year old). I'll probably change it out this month but I think it could go even longer.

 

[jgagel]

I have 2 - 10,000K DE Ushio bulbs using a dual Sunlight Supply Blue Wave ballast. I have fans blowing directly on the pendants to keep them cool. I have had them in service for ~14 months. I don't see any excess algae growth or any problems and since this is the first time I have come to a point where I need to change MHs, I don't know what happens when MHs start to become old. I know with NO bulbs, the spectrum shifts and algae will start to grow easier, same thing for MH?

 

[liquid]

I've seriously considered buying an inexpensive lux meter off EBay to get a relative measurement of my lamp output. That way I'd know when to change them out. IIRC, the rule of thumb is to change them when the light output is about 70% of the original intensity.

Shane