How old are my bulbs?

[PacificNorthWest]

Geesh, I've got 2x 315 CMH fixtures. And I've lost track of how old the bulbs are.

I know one is much newer than the other...so I want to replace one, but not sure which.

Can you visually inspect these bulbs to identify which one has been used longer? Upon inspection...it does seem that the gas ball on each bulb does appear a bit different. Do you think it's safe to say the one with more "brown deposits" is the one that has been used for longer? Or does this logic not apply?

I'll post 2 pics.

Any help is appreciated.

 

[The Phantom]

Do you have a light meter? Or maybe download a light meter app. You should be able to see a difference between the two to indicate which one is older, not as bright.

 

[PacificNorthWest]

I obviously gotta start writing dates on these bulbs... And no. no light meter. You can download cheap ones for cell-phones..?? I had no idea. Doing that now.

Very hard to tell which one is less bright with just eyesight

 

[The Phantom]

Other members have downloaded lux meter apps for their phones. Not exactly the most accurate but for you it would be enough to tell which light is brighter than the other.

 

[PacificNorthWest]

Phantom...you do man! Thanks! This should work.

 

[PacificNorthWest]

So. This didn't work. Can you guys lend any personal comments to the efficiency and the drop-off curves of these bulbs? I think I replaced one about a year after the other. Making one about 2 years old, and the other for about a year. This is all coming about because my last harvest was a little on the light side. Could be the strains though too as they were new.

I've read to replace these bulbs after 10,000 hours. Then I've read elsewhere that they can maintain 80% efficiency even after 30,000 hours. My HPS buddy said: "Oh definitely replace them after 2 grows".

But a year of 12/12 is only 4,300 hours. And I can squeeze in 4-5 flowers a year almost, so I think replacing 2x $120 bulbs after 2 grows might be a bit much.

Any suggestions? The phone lux meter was very close between the two bulbs, something like 620,000. But those min/max/avg numbers seemed to jump around a lot, and I couldn't quite tell which bulb was older.

Thanks for the chat guys!

 

[The Phantom]

The phone lux meter was very close between the two bulbs, something like 620,000.

Dang I was hoping that would be a quick way of checking. I'm drawing a blank on any other way to check.

 

[PacificNorthWest]

Strange that even a cheap lux meter from my cell-phone can't tell the difference between a year of gas burning away.

Cheers and thanks!

 

[JohnnieJC3]

The good news is... your bulb is probably fine... 2 grows seems short lived, CMH is good for roughly 20k in hours and known to go longer(HPS roughly 10k). The ceramic tubes are more efficient than HPS.

 

[PacificNorthWest]

The good news is... your bulb is probably fine... 2 grows seems short lived, CMH is good for roughly 20k in hours and known to go longer(HPS roughly 10k). The ceramic tubes are more efficient than HPS.

I am starting to think that too. I'm afraid that my lower yeilds this time around are a combination of two different new strains that I wasn't used to...and maybe a small pH imbalance / overfeeding near the end.

Anyway,. I bought one new CMH bulb today. I will install it and again read the lux readings from my Samsung phone sensor and post results...we'll see.

Cheers guys. And Happy Holidays!

 

[nivek]

i am curious about this because i just purchased a 630w cmh

replacing the bulb after two grows is bordering on absurd,, but don't tell buddy i said that, pls

now,, i have an app on my fone i use to compare one light to another,, nothing more. it can tell you certain things about your light, like output compared to another light, or like the light spread perhaps,, but not at all how much light your light is putting out

that being said,, it can tell you diffs between lights, as in light output compared to another light

as you figured out,, and both lights are putting out similar amounts of light

one is new,, one is old

why do you think you need to replace one at all, if i might ask?

karma sent friend

 

[PacificNorthWest]

why do you think you need to replace one at all, if i might ask?

1. Smaller buds than last time. Overall bud density lower than last time. My new Peyote Gorilla & Cream & Cheese 1:1 did not have the same bud density and size as my White Widow and Blue Widow run last time.

2. I couldn't really remember the last time I changed these bulbs. Was one changed 4 years ago and the other 2? Or was one changed 2 years ago and the other 1?

3. Will definitely scribe dates in my bulbs going forward.