In order to make this easy for everyone to follow I’m going to cover a few basics, hopefully it’ll help illustrate my point. This really is an article directed more towards fluorescent lighting than metal halide. I personally don’t like metal halide simply because of the heat generation (not that fluorescent lamps don't generate their own fair share of heat). When it comes to light, heat is always wasted energy.
Power
Electricity (a single phase, US feed) cycles at about 60hz per second. While this is enough to power a regular incandescent lamp, applying this current to other forms of illumination won’t work. Whether it’s fluorescent, high pressure sodium, mercury vapor, or metal halide, all these lamps use something else for their illumination that an incandescent lamp does not: Gasses. Unlike solid materials (such as a filament in an incandescent lamp) when a current is applied to a gas, it’s resistance to that current decreases, thereby raising its potential to conduct more current. This is one purpose of the ballast.
Ballast
So what’s does a ballast do? Well, a couple of things. A ballast will regulate the power being supplied to the lamp; ensuring that the lessening resistance of the gas does not allow more current to pass through until there’s an explosion. Magnetic ballasts would regulate this with a coil and induction, where electronic ballasts are more efficient (and they run cooler). Additionally, it changes that 60hz cycle of your normal power to 20khz and higher, ensuring the lamp appears to remain steadily lit. (Remember the bending pencil optical illusion in grade school? Older T12 fixtures operated at a slower cycle, meaning that flicker was all that much more apparent)
Lamps
Fluorescent lamps behave generally in the same way: Power is supplied to electron emitting fibers (sort of like a filament). Those electrons excite the mercury vapor in the glass tube, and ultraviolet light is emitted. That UV light then bounces off the phosphors coating the inside of the tube, and the end result, is visible light. Different combinations of phosphors and other gases allow for different lamps that reproduce various spectrums of light.
Now, why do supply stores charge from $200 and higher for a ballast? Probably because, most hobbyists don’t know better. All lamps, and all ballasts perform the same way. They have to, so the products you use for your tank behave in the same way similar products do in an office building, or a warehouse, and so forth.
On the subject of ‘overdriving’ your lamps. I really have to wonder why? Is there even really such a thing? Every lamp that I’ve ever seen ‘overdriven’ ended in an explosion. If you liken the concept to overclocking your PC’s processor, then you’ll have the same end, a significantly shorter life span. If you feel the need to overdrive anything, wouldn’t it be more cost efficient to add more lighting that operates at it’s nominal capacity?
I’ve since retrofitted my tank canopy with a custom made T5 HO lamp assembly. The lamps are from ReefGeek (A couple actinic, and some daylight lamps) The ballasts are Advance ICN-2S54 . I paid $20 for each. You can pick the same thing or similar products up at Home Depot, Lowes, or Grainger. Ballasts come in all sorts of ways, they’ll power various types of lamps, and in various quantities. (If you check out the spec sheet you’ll see that my one ballast can drive 5 types of lamps, in quantities of 1 or 2) Some ballasts are smart, and can operate under either a single or three phase feed. There are other comparisons you’ll want to keep in mind, like the THD, Size, Weight, and so forth.
Now, don’t just go out and buy something without doing your homework. The products you get from various marine/reef stores do take a lot of the think work out of it all. You’re given wiring harnesses, corded plugs, and so on. When I bought these ballasts, all I got was the ballast in a box. You’ll have to be prepared to follow a wiring diagram (they’re easy) and make up your own wires. Be sure to match the ballast with the lamps, T12, T8, T5, SO, HO, or VHO to ensure no mistakes.
Well, hopefully this will help some of your wallets. I don't claim to be an expert, so if there's anything else someone can add or correct me on, I'm all ears.
Power
Electricity (a single phase, US feed) cycles at about 60hz per second. While this is enough to power a regular incandescent lamp, applying this current to other forms of illumination won’t work. Whether it’s fluorescent, high pressure sodium, mercury vapor, or metal halide, all these lamps use something else for their illumination that an incandescent lamp does not: Gasses. Unlike solid materials (such as a filament in an incandescent lamp) when a current is applied to a gas, it’s resistance to that current decreases, thereby raising its potential to conduct more current. This is one purpose of the ballast.
Ballast
So what’s does a ballast do? Well, a couple of things. A ballast will regulate the power being supplied to the lamp; ensuring that the lessening resistance of the gas does not allow more current to pass through until there’s an explosion. Magnetic ballasts would regulate this with a coil and induction, where electronic ballasts are more efficient (and they run cooler). Additionally, it changes that 60hz cycle of your normal power to 20khz and higher, ensuring the lamp appears to remain steadily lit. (Remember the bending pencil optical illusion in grade school? Older T12 fixtures operated at a slower cycle, meaning that flicker was all that much more apparent)
Lamps
Fluorescent lamps behave generally in the same way: Power is supplied to electron emitting fibers (sort of like a filament). Those electrons excite the mercury vapor in the glass tube, and ultraviolet light is emitted. That UV light then bounces off the phosphors coating the inside of the tube, and the end result, is visible light. Different combinations of phosphors and other gases allow for different lamps that reproduce various spectrums of light.
Now, why do supply stores charge from $200 and higher for a ballast? Probably because, most hobbyists don’t know better. All lamps, and all ballasts perform the same way. They have to, so the products you use for your tank behave in the same way similar products do in an office building, or a warehouse, and so forth.
On the subject of ‘overdriving’ your lamps. I really have to wonder why? Is there even really such a thing? Every lamp that I’ve ever seen ‘overdriven’ ended in an explosion. If you liken the concept to overclocking your PC’s processor, then you’ll have the same end, a significantly shorter life span. If you feel the need to overdrive anything, wouldn’t it be more cost efficient to add more lighting that operates at it’s nominal capacity?
I’ve since retrofitted my tank canopy with a custom made T5 HO lamp assembly. The lamps are from ReefGeek (A couple actinic, and some daylight lamps) The ballasts are Advance ICN-2S54 . I paid $20 for each. You can pick the same thing or similar products up at Home Depot, Lowes, or Grainger. Ballasts come in all sorts of ways, they’ll power various types of lamps, and in various quantities. (If you check out the spec sheet you’ll see that my one ballast can drive 5 types of lamps, in quantities of 1 or 2) Some ballasts are smart, and can operate under either a single or three phase feed. There are other comparisons you’ll want to keep in mind, like the THD, Size, Weight, and so forth.
Now, don’t just go out and buy something without doing your homework. The products you get from various marine/reef stores do take a lot of the think work out of it all. You’re given wiring harnesses, corded plugs, and so on. When I bought these ballasts, all I got was the ballast in a box. You’ll have to be prepared to follow a wiring diagram (they’re easy) and make up your own wires. Be sure to match the ballast with the lamps, T12, T8, T5, SO, HO, or VHO to ensure no mistakes.
Well, hopefully this will help some of your wallets. I don't claim to be an expert, so if there's anything else someone can add or correct me on, I'm all ears.
