bulb life span

Howdy all.
I use 400 MH bulb for veg and 400 hps for flowering. Have used the 400MH for approximately 1200 hours on previous grows. Is it time to buy a new one? How long is the productive life span of these bulbs? can anyone help? got an ak48 grow on the way. just germinated.
peace from Afro clown.

After 12 months of use at 18 hours per day, a 1000 watt metal halide lamp should be replaced as it is only about 85% as bright as the day you bought it.


Yes that is about a 1000 watt bulb but their life expectancey is not much different for different wattages so figure it out yourself.

your good no worries

1200 hours? well it depends on your brand but most manufacturers say about 15000 for MH bulbs and they start loosing output a little after their halfway point and since your only veggin with it, you could probably take it to ten thousand hours if its a decent brand bulb, but i would replace the hps bulb once it starts loosin light, you want them buds to get ALL the light they can get when flowering.

thanks and have noted.
peace and happy growing.
afro

Here is some more info.Scroll down to the second to last question.OPH

http://cheapgrowlights.com/FAQ.html#How_long_do_MH_and_HPS_lamps_last_When_should_I_replace_my_lamps