# metal halide advice needed



## seafood (Jan 25, 2006)

I'm considering setting up an open-top tank with MH pendants. Currently, I have two closed-top tanks with compact fluorescents. They're doing pretty well. 

My questions:

How often do MH bulbs need replacement? I replace my CFs annually. Will MHs last longer or not as long?

This tank will have, I hope, high-demand plants. Is the 3-watts per gallon rule of thumb still relevant with MH?

What are others' experiences with MH v. compact fluorescents? Are MHs better/worse/same?

Thanks everyone!


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## Damon (Jan 18, 2005)

No experience with metal halides but I do know..........
Lighting is more "direct" than power compacts. 
Gives off more heat
Hard to find spectrums you want
More expensive
May not be able to find wattage you want.
Unless your tank is 90+ gallons, I would stick with pcs.


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## cheseboy (Aug 5, 2005)

Yeah, metal halide is mainly a lighting for reef tanks where they need an excessive amount of lighting. Just make sure you don't have an excessivly high a wattage on a planted tank or I beleve the plants will not benifit.


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## Daniel (Feb 17, 2006)

be aware that if you fire upo the light and there is a momentary loss of power and then it comes back on the bulbs blow-they need 10-30 min cool down before restarting.

we run lighting towers(motorway maintaince etc) so I have experience with this kind of bulb failure regularly and the bulbs are not cheap.


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