MH bulb question

[escape2thewater]

How long do MH bulbs usually last? Do they need to be replaced like VHO/etc?
Thanks,
Kyle

 

[jarvis]

I belive they are good untill they just burn out. Some bulbs even gain PAR with age.

 

[reefnut]

Depends on the bulb. I think a 10k needs replace once a year and a 20k about every 6-8 months. The bulb will "light" for longer than that but you loose spectrum.

 

[bigmac]

It depends on the ballast your using. For the most parts ReefNut is close. 10K's should be replaced once a year. Radiums (the only good 20K bulb) 6 months tops ran on an HQI ballast, 12 months on a standard or pulse start ballast. The Iwasaki will go 18 to 24 months with no problem and even after 24 months look as good as a new bulb.

 

[dburr]

I belive they are good untill they just burn out. Some bulbs even gain PAR with age.
No, bulbs lose spectrum over time. Most manufacturers recomend 12 to 18 months before changing.