just been trolling the web and have struck me with a question

i know you can get halide flood lamps and they can range in wattage from 70 to 400w etc

but what is the difference other than the price of them

i am sure if you were to change the bulb from a floodlight to a 10000k one it would work the same as a halide made by arkadia or am i completly off my nut

it is just you can buy the units for ?30 as opposed to 100 for the same sort of reflector

i dont understand how these all work

and what the difference would be

how can you tell murcury ballasts from electronic and magnetic

Thats pretty much correct, tho your last sentance is a little confused. There are "electronic ballasts" and "magnetic ballasts", the latter use a whopping great transformer/coil and couple of other components and weigh a tonne, electronic ones are more, well, electronic! AFAIK, you can get either type for halide, sodium or mercury based lamps, but as you have guessed, you need to pick a ballast that is compatible with your lamp type, basically, avoid mercury ones particularly when considering magnetic ballasts. When it comes to the magnetic ballasts, the unit should be marked accordingly, usually the coil is marked.

Magnetic ballasts tend to generate a little more heat, use a little more electric but at the same time burn the lamps a little brighter, When/if they break they are cheap as chips to repair. Burning/overdriving the lamps isn't necessarily a problem.

Electronic ones still generate quite a bit of heat, waste less electric and don't over-drive the lamps.

The industrial flood light units can work very well providing you can find a unit that is not too bulky and astheticly acceptable.

Of course, you can always but the bits to make magnetic ballasts and separate reflectors, I used these for many years.

Chris

cheers for that chriss
what about these http://cgi.ebay.co.uk/250W-METAL-HALIDE-FL...id=p3286.c0.m14

would these be magnetic or electronic and would these use sodium or murcury ?

where i am putting the tank i have a deep recess that used to be a fireplace where all equipment like this would go also as it is right near the fuse box i can run it on a seperate supply from the tank

i have been looking at the luminarcs but was looking for a cheaper option for the short term while i save lol

Well, it seems like it would be suitable particularly since it states 'metal halide', might be worth asking the seller to check the it is 'suitable for metal halide or sodium lamps and NOT mercury' just in case!

Chris