HPS bulb lifespan?

[YardDog35]

I have a Hortilux Eye, 400w hps bulb that has illuminated 4 grows now. I know its says something like 24,000 hours, but I thought I read somewhere they are only good for so many cycles before they loose efficiency.

Thanks!

 

[LEDman]

Since all HID bulbs degrade over time (meaning they draw the same amount of power but output less lumens), a general rule of thumb would be to exchange bulbs after half their advertised lifetime (in your case, 12,000 hours).

I have read that a lot of growers exchange their bulbs after two grows; depending on how much you pay for electricity and how much bud you want, you may find this economical as well.

 

[harrywaless]

It is well documented and tested that the bulbs lose their intensity within the first year or two. I'd follow harrad's advice, his numbers are right on.