What to look for hps bulb dying!

I have an hps set-up currently and was wondering other than the obvious dulling of the light over time if there's any other telltale signs that one can look for that dictate a bulb change? I didnt have my bulb when its was purchased, was wondering if anyone with a few hps grows under there belt can awenser what to look for even if there subtle things to loook for. Please and thankyou.

most HPS bulb have 8000 to 16000 hours of life, but after 3-4 harvest it's good to change the bulb as it loose some lumens.
when the bulb gets old, the inside tube truns black at the ends. the blacker it is, the more miles on her.

ahh excellent! By the way. I'd kill to get some of those caps like you got in your pic there yummy!

When it's finished it doesn't blow or anything. It will shutoff and try and re-strike and keep trying over and over again.

the inside tube truns black at the ends. the blacker it is, the more miles on her.

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looks like i need a new one soon then.

Good info!