Light output question

[chbix]

Ok so my third post of the evening (well its 3am so really morning) had to do with lighting.

I need lights to have coral, so looking around and trying to "cheapen" the blow. I have seen alot of power compact lights and think I like these. So listening to other posts I have read I gather that I need at least 4 watts per gallon of light. 55 gal would require roughly 200 watts of lights. Stop me if I am way off here.

So Looking at some PC and T5 lighting setups, I see that I can get a 54watt X 4 bulb set up. So that would put me at almost exactly the right level for 4 watts per gallon. Am I following this right? I have also noticed that these are usually set up in 2 sections, meaning there is one switch for two lights and another switch for the other two. So the most common light setup coming with these lights are two 10000K bulbs and two acitinic (sp?) bulbs. From research it seems that the acitinic bulbs are to make the corals "wake Up" simulating the sun rise and some youtube videos have these lights come on 2 hours before the 10000K and then run the 10000k for say 6-8 hours with the acitinic still on and then the acitinic run for an additional 2 hours or so.

So during that 6-8 hours when all 4 lights are running the tank is getting its required 4 watts per gallon?

Also how important is moonlighting?

I have found some hoods on ebay that look to be for hydroponic applications and all come with 6800K bulbs, would these handle a 10000K + bulb?

 

[chbix]

Ok so I just thought of another thing. My tank is 48" long, how important is it to have lights that go the full 48"? if for example I got a 36" light setup and hung it over the tank.... Obviously I realize that I cant mount a 36" light hood to a 48" long tank.

 

[chbix]

Third question, if I get a setup that says it uses 4x 96 watt bulbs, do I have to use 96 watt bulbs or is it like a standard bulb and thats the max you can use? I think thats what it is but when spending this kinda cash I want to make sure I understand EVERYTHING!

 

[BL1]

When it comes to PC vs T5HO vs MH, your much better off passing on the PCs. Yes, the wattage output may be similar but, the amount of usable light and PAR (photosynthetically active radiation) is much lower with PCs than your other two options. What does that mean, it means that you would be limited to the less light intensive corals. Also, while using watts per gallon is a good general rule of thumb, it is a somewhat out dated way to figure out reef lighting. This is because some methods of lighting ie. T5s with individual reflectors or MH lighting will penetrate deeper into your aquarium making them more efficient than say PC lights or T5s with a single reflector.
As far as using a 36" fixture on a 48" tank, you can ... but, it will just cause your tank to have a "spotlight" look in the middle. It will also restrict you from keeping corals on the outside edges of your tank.
Moonlighting from everything I've read is still a highly debated issue with not much actual research. Some people argue that corals need the moonlighting to simulate actual conditions in the wild, others say that moonlighting is strictly an ambiance thing. Personally, I enjoy watching my tank under moonlights.
Here's is a pretty good article I found to read about the basics of lighting for ree aquariums: Aquarium Lighting; Kelvin, Nanometers, PAR, Bulb, Watt, MH, LED, Light Basics.

 

[Bifferwine]

Go with T5s over PCs, for the reason Brian mentioned. A 4-bulb, 48" T5 set up will be perfect for a 55. If you get a 36" setup, I think it will look weird, and you will be limited to keeping corals in the middle of the tank.

I would pass on the 6500K bulbs. Those will make your tank look yellow and brown. If you want to see the colors in your corals, go with a mix of 10000K and actinics.

Another thing to consider is individual reflectors. Some T5 setups have individual reflectors around each bulb, which greatly increases the light output, without requiring any additional energy usage. For example, a 6-bulb T5 setup with individual reflectors is a better choice than an 8-bulb T5 setup without.

 

[bjohanson1234]

Third question, if I get a setup that says it uses 4x 96 watt bulbs, do I have to use 96 watt bulbs or is it like a standard bulb and thats the max you can use? I think thats what it is but when spending this kinda cash I want to make sure I understand EVERYTHING!

Just an FYI, flourecent bulbs arent like regular incandecent bulbs. Their size and wattage are pretty much fixed. If the fixture says it uses 96 watt bulbs then that is the size you ned to get. The bulbs match the ballast.

 

[chbix]

Thanks guys, I will look more at the T5 lights!

 

[chbix]

so Looking around i found this T5 HO FLUORESCENT 44 4 LAMP 4ft GROW LIGHT BULBS 4' NEW - eBay (item 320581874028 end time Aug-29-10 19:00:50 PDT)

Or

This
Odyssea T5 High Output Lighting

I put a bid in on the ebay but if i dont get i think ill just get the other one.

 

[BL1]

I don't believe that first fixture is meant for reef tanks. The second should be good though. I just bought a light from aqua traders for my tank. While it's not the highest quality light you can buy (you get what you pay for). It's still a great fixture for the price.