When to change a MH bulb?

[dugg]

Ok, i have heard 6 months, 1 year, and 1 1/2 years. What would be the general consensus here?

 

[JR719]

With my Ushio's, I was told 8 months. Now with my XM's, I'm told 1 year. I only run them 6 hours a day.

 

[dugg]

My Hamilton runs 12 hrs and is at 13 months now. I have a new bulb, just didn't want to toss a good bulb. I'm sure i will see a difference after i change it, but for now it looks just as bright as the day i installed it.

 

[JR719]

I'm not positive, but brightness will be just a little less if even noticable. It is mostly spectrum shift that causes one to change the bulbs so often.

 

[Travis L. Stevens]

I wouldn't go long than one year. I noticed a decrease in growth between the 8 month and one year area. 1.5 years in and things are at a stand still. 2 years and I'm starting to lose some Zoanthids and recession in other corals. My new bulb will hopefully be here this weekend.

 

[dugg]

Well, i stand corrected. The new bulb is so much brighter then the old one, there is no comparison. Like the sun and a 50 watt soft white bulb lol. I guess my next one will be changed around 9 months or so.