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Re: Metal Halides In Australia

>How good are they? They're fairly pricey - the best I could find was
>around the $500AUD mark for a 150W double ended version (5200K or
>10000K). How much heat do they produce? Apparently they have a remote

Arg, forgot about that heat question in there... The MH core+coil 
(synonymous with big+heavy :-) ballasts are usually about 80% efficient if 
you go with the nameplate load numbers and the wattage on the bulb. For a 
175w ballast then you're going to be putting out about 35 watts of heat 
*from the ballast alone*. Yes, the ballast will get HOT. I just complete a 
new 3x175w ballast system and the ballasts get too hot to touch (the core 
itself, not the enclosure it's mounted in), and I have them mounted to 
allow maximum convection cooling *all* the way around each ballast. In 
normal operation this isn't really a problem since the metal case doesn't 
care about the heat, and the ballasts are built to tolerate the heat they 
produce. The electronic ballasts are supposed to run cooler but I haven't 
played with any myself.

You'll want a remote ballast, which is pretty typical for aquarium MH 
lights. The ballast will be heavy and fairly large, and you'll want to be 
able to put it away from the hood.

The reward you get is the best lighting on the market for aquariums, IMHO 
:-) I'm big fan of MH lighting.


>Adam Shaw

Waveform Technology
UNIX Systems Administrator