Mercury Vapor??

[deano488]

I was reading a reef keeping book copyrighted in 1989 and it spoke of mercury vapor lights. I have never heard of this and was curious if they are still being used or if anyone knows about them... It said in the book that they are (were) a more economical, almost as good, substitute for metal halides.
Dean

[RicksReefs]

see the yellow street lights? those are MV.
they'll grow brown coral and algae pretty well.