Please excuse my lack of knowledge when I ask this question, I'm still quite new to this.

I bought some 400w HPS bulbs which had been used for approx a week before being replaced with 600's (or at least that's what I was told). I was wondering if there are any visible signs that show the age/usage of a bulb?

There are burn/stain marks on the bulb and the white bit inside looks very dark at the edges. Are these signs of age and use?

Thanks for any replies.
Loafyboy Reviewed by Loafyboy on . How do I tell if a HPS bulb is spent? Please excuse my lack of knowledge when I ask this question, I'm still quite new to this. I bought some 400w HPS bulbs which had been used for approx a week before being replaced with 600's (or at least that's what I was told). I was wondering if there are any visible signs that show the age/usage of a bulb? There are burn/stain marks on the bulb and the white bit inside looks very dark at the edges. Are these signs of age and use? Thanks for any replies. Rating: 5