Hps Hortilux Blues

[dorjewright]

Every HPS Hortilux blue ( 600s & 1000s) I've used in the last year has developed a black shadow on the lower surface of the glass after a few months - like mid flower. Anyone know what's up?

 

[ken dog]

A burn mark... Probably from touching it with oily hands.

 

[dorjewright]

My mistake its not a "blue" just regular hps.
I always clean my bulbs and use a clean rag to install. I don't think that would explain the same shadow on all the bulbs - run the length of the underside (as installed). But maybe.

 

[Smokey503ski]

Do all your lights come on at once, or do they self stagger?

 

[dorjewright]

All at once.