Mh ? 250 watt

[Dewey]

Is there a top or bottom to a single ended MH bulb?

Thanks Dewey

[ellisz]

Not that I am aware of. Just screw them in.

[juskeepswiming]

is this a trick question?

[Dewey]

No trick ? I was thinking that someone said there was.

[MT79]

I've read it' is best to position them w/ the nipple facing up. I can't remember exactly why, but one of the reasons is it could negatively affect the k of the bulb if it is not. HTH

[Brenden]

All mine are horizontal. What kind application would you need it straight up and down? The majority of the light comes from the sides.

[MT79]

What kind application would you need it straight up and down?

I'm referring to the nipple on the inner part of the bulb- the fixture is still mounted horizontally over the tank(..if I'm understanding you right).

[Brenden]

got ya

[MT79]

Looks like there is more to it than just nipple orientation. Here is an informative read "Nipple Nonsense"
http://www.advancedaquarist.com/issu...ductreview.htm

[Brenden]

Nice article. Thanks In short...just screw it in.