Grow bulb usefull lite lifespan question

[dontknownuttin]

I read about hid and MH bulb life. I understand the useful life of a grow bulb is limited. How many grow cycles do you get out of a bulb? Also, how many keep a spare bulb around?. Does anyone donate the used but still working bulbs to low income growers?

[Karlee]

Funny you ask don't

Bought a new hps bulb today the store person told me the MH can blow up after a year and they have mercury or some shit so every year change the bulb.

[Weasel]

I change mine about once a year. I've gone more than 18 months on a bulb and when I changed it there was an obvious difference in brightness. But even a year old bulb grows dope almost as well, in my opinion. At least- any decline in production is subtle enough that I could never see much difference. Apparently after a year most bulbs decline by about 20%. Which sounds about right to me. Higher quality bulbs last longer, I think.
I think once a year is about right. Save the old ones and label the date near the base with magic marker so they don't get all mixed up.
As for them exploding - I think that's false info.

[South Sierra Dude]

I think the manufacture recommendation is two or three grows depending on how hard you are on them.

[kingfish]

I keep my HPS bulb for 2 years. I average about 3 grows per year. I will be done with my finale grow sometime in March. I just got this bulb at the start of the year and will keep it for another year then replace. I also just replaced my ballast. I've had it for 5 years.

[South Sierra Dude]

Good to hear. I'm still on light one. Light two is in a box.

[Karlee]

On exploding HIGH pressure lights

[Weasel]

Karlee that link didn't work for me but the fact that you put it there must mean that someone says bulbs do explode sometimes. I've just never seen it happen or heard anyone talking about it online in the last 10 years or so that I've been growing.
However once I did have a bulb burn out and disintegrate to the point that the outer glass casing was dangling from the ruined socket when I found it. It was a newish hps bulb- good quality and no particular reason other than random failure. It looked quite scary but luckily didn't cause any other damage or fire.

[Karlee]

I want us safe Weasel It seems we don't hear all the news we should.

[Weasel]

We tend to be naturally scared of those huge high wattage bulbs, which no doubt is a very good instinct. Just be safe with electricity, keep clean connections, don't overload circuits, make the grow as fire resistant as possible and if there's some slight risk of older bulbs blowing up- that's just one more reason to change them out after a year or so, but I think in reality such explosions must be very very rare and not something to lose sleep over.