info on ballasts please

[argan]

Hello ppl, i was looking at a used building supply store today and say some 175w mercury metal halide bulbs for $10, i was wondering if i find a fixture do i need a ballast? Also the bulbs have a white coating on the inside, will that affect the output a lot?

[reef_guru]

ballasts are needed for mh. electronic ballasts will start anything and the white coating will effect the light produced. better off to buy new bulbs and not use the old ones, most mh bulbs only last 8-2 months

[Tangster]

Originally Posted by argan

Hello ppl, i was looking at a used building supply store today and say some 175w mercury metal halide bulbs for $10, i was wondering if i find a fixture do i need a ballast? Also the bulbs have a white coating on the inside, will that affect the output a lot?

You need a proper ballast to fire what ever bulb you need and I get 2 yrs on average from any M/H I ever used and 3 yrs on some as for the use of a 10.00 Mercury vapor bulb That will not do to cool in the spectrum to mush red and green you want a Hotter K like a 10.000 K at least the K is Kelvin thats how they rate M/H bulbs and all bulb really.

[aquaboy]

I wouldnt use a bulb from a building supply store, cause they need to be "of the proper spectrum" to have any benefit to a REEF tank. most non-aquarium bulbs are around 4000K and appear like a yellowish color. id just play it safe and use bulbs made specificallly for aquariums.

[argan]

so the wattage doesn't matter as much as the spectrum?

[aquaboy]

the wattage (output per watt depends on light type) and the spectrum matter. how big is your tank? you could get a core and coil kit for ~$50, or an assembled ballast for ~$100 or more. Most ballasts you buy will fire Standerd Metal Halides. you could also get a mercury vapor ballast for around the same price. I would go with standerds IMO because of spectrum choice. a 14000K bulb is a good bulb IMO because it is a nice white/lightblue that lessens the need for actinics. whilst a 10000k is ice white and a 20000K is a deep blue. Ballast choices are almost unlimited. Go to the website i posted at the end for a good and semi-simple description of how they work and what ballasts are best for what bulb, i used it and now i know what im gonna do.

Light info

[Tangster]

Originally Posted by argan

so the wattage doesn't matter as much as the spectrum?

Wattage is like water pressure more wattage you have the more penetrating the light is and the further the spectrum can travel.. And the spectrum can be related to the temperature of the water .. Hotter are the white to Blue end of the spectrum the cooler temps are the at the point the white and blue starts to go to yellow and reddish orange to green.. Like a cutting torch tip at the very tip where the flame is the hottest its blue then as it cools it goes to a white then to orange to red like a gas range burner also.. Our sun is a cool star it runs about 6 Kelvin and a super Nova is white hot and 10 Kelvin and the Blue super burst Novas are like 20K and they hit up wards of 10x's the temperature of our cold old sun (: Confused yet ? you will be