Plant growth metal halides for corals?

[msumatt]

Hello,

This is my first thread ever here so be kind. I'm starting a frag tank and have the construction almost complete. The one problem is the lighting. My partner has an old metal halide and something light (I think high pressure sodium) that he's giving me to use for the frag tank. I've never worked with halides so not sure about them and can't find this answer anyway so I'm asking it here to the smart people of captive reefs. I'm just going to use the metal halide part, which is 400 watts, but don't know if the light that is in there can be used for my corals. Anyone know if a metal halide that is good for growing plants, good for growing corals? In other words, other than watts, are metal halides all mostly the same, for example I can't find actinics for them anywhere, so I'm wondering if they have different kelvins at all and what kind of metal halide is best for the frag tank. That's a lot of info so I'll end it now by saying thanks for any help anyone can provide.

[larryandlaura]

Metal halides are great for coral and plant growth. There are different color spectrums and bulb types. What are the dimensions on your frag tank?

[msumatt]

It's about 30 inches long, 12 inches high, and 12 inches deep.

[Heidi]

400watt Metal Halide is great for growing coral. I would buy a new lamp (light bulb) for it from a place that sells aquarium lighting. If you buy a 15k 400w lamp it will be bright and a nice blue color and work just fine in your fixture. Just make sure you buy the right kind of base (mongol or that double end kind..not sure what its called) to fit you fixture. I hung a similar light fixture from a hook in the ceiling over my hex and had amazing color and great growth. Pendent light fixtures are sold for hundreds of dollars but sounds like what you have will do the same thing once you replace the lamp.
Hope that helped
Heidi

[msumatt]

Thanks so far for the helpful responses. After looking some more I had found more info about metal halides and kelvins. I basically decided to split the difference between 10000 and 20000, but I'm torn between 15000 and 14000 K. Any particular difference between those 2? I want my frags to do the best possible. Thanks again for the help so far.