Hmm well I've got some time so I will try to do my bvest in telling you whats out there, but to let you know you must invest pretty decent amount of money into lighting, just about the most important thing in your tank, sitting side by side with water chemistry. Anyway here we go! Oh yeah.. moderators and advisors if you see any flaw or need to change something about this messege instead of just posting please do.. it'll be easier for people to read a single more correct source of info than read this entire thing and then have to unlearn something bad and reread elsewhere... but if its just prefernce than post below!!
Lets start with metal Halide, essentially the best light you can get for corals, good choice. Most people are led
to believe you can grow quality stuff with only PC
's and in my opinion it isn't true, though you can grow SOME stuff under PC
's, its by no means a replacement. First off we'll begin with the ballast. The ballast is just a box that converts the full electricity from the plug into the proper strength needed to light the bulb. There are different ballasts, and I wil try to ecplain them in simple terms. That I know of there are two types of ballast, one called a magnetic ballast, and the other called electronic. You'll be surprised to see the price differences of the two.
The magnetic ballast is known to slightly over power the bulbs which makes them a bit brighter and leaves the bulbs with less life. The pros to this is that instead of getting the said light on the package you are actually gettiong a bit more (hence comes more intensity from the bulb). The con to this is that you will have to replace bulbs faster which is quite costly. In my opinion it is a bit expensive to have to spend more electricity AND bulbs. Most people kinda forget to add not only the electricity bill part of it (which isn't much at all) AND the added costs of replacing bulbs (which is A LOT). The magnetic ballast also typically has to be cooled, except for the more "better ones you can buy", plus they make more noise.
The electronic ballast sends a steady stream of power that does not fluctuate and really doesn't go over the power it says it gives to the bulb. On top of that they run a bit cooler, to some opinions. They also produce less noise, which is goof for the people who like to keep the ballasts in the hood along with the fixtures (which is something I wouldn't do). As for power and what the bulb actually produces because of the ballast there is a chart out there which I will try to find for you to see the differences in the ballast AND bulb.
Okay the in betweens of the ballast and actual hallide bulb is the socket, which can be picked up at just about any online store that sells lighting products like Hellolights.com, AHsupply.com, etc. (the two first companies are very good, I just ordered from hellolights.com and could not be happier). But this now leads to another short difference... sockets and bulbs. To make the world a bit more complivated there are two types of sockets/bulb ends to hallide bulbs. One is called a single End (SE) and the other is called a double end (DE). Its exactly as it sounds, just that one bulb has two ends to it while the other bulb has one. From what I understand the DE bulbs run a bit more power than typical SE bulbs. Again this is a prefernce issue to me, I have no experience with DE bulbs, most people use SE bulbs because they may find little differecne that it does not exeed the slightly higher costs of having DE bulbs.
Okay now we run into actual bulbs! There are two things with bulbs.. one it what wattage they run at which are typically 175, 250, and 400 watts. There are those that run more wattage but this is what most people typivally use, plus in the 400 range the bulbs do get super hot, which increases evaporation like crazy... (i.e. its very difficult to cool).
The next thing we need to discuss is the Kelvin rating of the bulb, which is known as color temperature. The suns kelvin rating is around 6500K. The lower the kelvin rating the MORE intense the light is. So of course I thought well heck shouldn't I go for THOSE Kelvin rated bulbs... I wish! But there is a huge consequence that follows lower Kevin rated bulbs... the COLOR! The lower the Kelvin rating means the much more yellower it looks, and to all reef people its a nightmare.. it makes our reefs look oogly. The bulbs out there are 6500K, 10000K, (some bulbs have in betweens like 14000K and such but is a bit more rarer), and 20000K. I think you will find that most reefers use a combo of 10000K buklbs with actinics (I will discuss that soonly). But why choose 10000K... is there something special about... well like everything in this world.. preference!!! As you climb the kelvin rating the color goes from yellow to blue, but remember the light also gets less intense. This is one of the many reasons 10000K is used... the fact that people like intensity the corals are recieving from these bulbs, and with the added actinics (we'll think of it as blue light for now) the colors in total look fantastic. But what of the 20000K!?!? you ask... well there are also people who LOVE the mega blue color 20000K bulbs give off. There are also people who believe that actinics are just NOT needed with these bulbs because of the blueness they already give. SO to wrap up.. higher kelvin rating bulbs like the 20000K give off more blue color but are less intense, while the lower kelvin rating bulbs are yellower but are more intense (like the sun). Now we jump into the actinics, which involves VHO
's vs PC
Okay dokey... first thing off to make your purchasing experience a bit easier from the get-go, when you do order actinics make sure they are 03
's, its a bit difficult to make it siumple... but they are more true bluer.. much mor ethan the so-called "day actinics" or the 50/50 actinics, or even the "super actinics". If you don't see the 03
, then I suggest you look somewhere else for them. Well after stating that you'll want to know why you should get actinics. In my opinion I believe corals love actinics. It suits both the owner of thr aquarium in coloring the water to their preference, the corals love more light... so yay a nice little agreement on both sides... but is there anything else!? Sure. Reefers (including moi) will have the actinics turn on first to imitate dawn, then ahve the halides turn on about a half hour to an hour after the actinics come on, then towards the day's end the halides will turn off but not the actinics... making dusk, and then eventually turning off the actinic 03
's about a half hour to an hour after the halides turn off to make it night. I'll mention it later but I use moonlights (which is easy to make on your own plus its spectacular.. tell you later).
The ballast to these actinics are NOT the SAME as the hallide ballast. You must remember this as some people either get the wrong ballast, or begin to wonder why some ballast have a wattage rating of something like 440 watts as opposed to just 400 watts. SO keep in mind that there are different ballasts for metal halides AND actinics like VHO
's and PC
's. So what are the differences between these two guys?? Well the VHO
's are bigger... but not as powerful as the PC
's in my opinion. I chose to go the PC
's route because others perferred them over VHO
's. Hopefully others can give you better info on this as I can;t really see to much other reason to pursue other than what I have just said (i.e. more than needed to know) :P Again you can get the parts: ballast, bulbs, ad end-caps from any online store that sells lighting supplies.
Moonlights.. I love'em and just about everyone else does too. Its claimed that fishies can't really see blue light, but semi make out the outlines of other objects when in it (water with blue light). Its also theorized that they help out the corals some... but don't hold em to this. Why is this god you ask.. well the ocean isn't always pitch black at night. Also fish injuries can be caused by them running into stuff or worse.. eachother which can start scared fights or just the fish going spastic on you and running into other things. The really cool thing about moonlights is that you can now see your own tank at night and even best of att is that now those frieds who want to see your tank at night, and ask the painful question "please, can you turn on the light for just a second" won't ask it anymore. SO far so good? yay! there aren't any cons to having moonlights that I can see... even power consumption wise it takes VERY little wattage to pull this off, and even easier to just make them yourself. You now may be wondering... why not just use a single actinic bulb or something to that nature? Well even those lights are much to powerful and you will stress the corals AND fish. There is a post, very long post, about moonlights to get your answers desired about them, plus they also mention on how to build it too, and again I can not stress how easy it is to make and install.
Now about to getting these parts and setting them up. If you want to try to save money I guess you could try ebay, but I have a hard time getting any set up used.. especially if it is the bulb themselves.. unfortunately it is very easy to lie about the life of your bulbs.. so I just stay away from it to make it easy. The actual set up you choose with be due to your prefernce... but look around and see what the people out there say. When you get your items just come on the messege board and ask about set up, its not too harsh ot anything
Anyway good luck!