How often do you change out your MH bulbs?

[Kaos]

I did a search on this and didn't really turn up anything. I have a 175w SE setup being run on an IC ballast. If I remeber right I think I've read that MH bulbs need to be changed out every year due to spectrum shifts and loss of PAR.

Anyway, how long is everyone going before changing their bulbs? TIA.

 

[polwick]

Good question, I have a similar setup and would like to know the answer. My LFS says 6-8 months, but I'd like more opinions.

 

[McCrary]

I change mine out about once a year.

 

[Kaos]

In some of the research I've been reading it seems they decline rather quickly. But it also seems to depend on the bulb manufacterer and the ballast used. There are really too many variables to be able to get a rule of thumb. I think I will just monitor my corals and let them tell me when it needs to be changed. But I doubt I will go over the year mark.

 

[jer77]

There are many variables in MH bulb life. I've found that higher kelvin bulbs lose par and shift their spectrum more over a period of time than lower kelvin bulbs. I try to change my bulbs once a year, but 8-10 months is better, especially for the higher K bulbs. Just be careful when replacing the bulbs that you do it slowly and acclimate the corals to the brighter light. I have had many corals slightly bleach when I added new bulbs.

 

[nick18tjetta]

The major shift is in the begining of the bulbs life. After 1 year, the bulb is only going to loose 3-5% of its par values and will probably not shift in its color spectrum. That said, I run my Halides 2 years.

 

[bladze]

9 months. After 9 months, you can tell right away.

 

[gasman059]

I just cahnged mine after 8 months- and yes there's a noticeable difference -BTW XM's 20k 3x 400watts