When to change bulb?

[krustythfreakinclown]

I have a 400W HPS bulb which has been used for 3 grows: about 1 month at 18/6 and 2 months at 12/12, per grow.

When should I change the bulb?

Does the bulb just burn out, or does it give warnings that it is waning?

krustythfreakinclown Reviewed by krustythfreakinclown on 05-29-2006. When to change bulb? I have a 400W HPS bulb which has been used for 3 grows: about 1 month at 18/6 and 2 months at 12/12, per grow. When should I change the bulb? Does the bulb just burn out, or does it give warnings that it is waning? Rating: 5