10000 or 6500

[sauer]

whats the difference. I am doing a 10gal and was looking at a 2-36watt PC setup.

[Rocket_155]

Have you done a search?

 

If you had then you might have nown that 10,000K is white light and covers the full light spectrum. 6500K is very yellow and covers just the yellow light spectrum

[sauer]

I know that. But what does that mean as far as what I can keep, or which is preferred.

I want to house LR, LS, a fish or two, and corals.

[sjpresley]

There is no difference as far as the corals survival is concerned, just their appearance. You can keep anything under 10K that you can under 6500, it just a matter of personal preference.

[HuBu]

youll probably like the 10k since its white. try searching online, there are sites that compare how certain bulb temp compare with one another.

[tinyreef]

the choice of bulb spectrum is more up to the reefkeeper for aesthetic reasons as long as the minimum lighting requirements are met. the lower temp bulbs (<10000K) are typically more pleasing to the human eye as they render colors more like the sun (4300K?), very red/yellow/green. the higher temp bulbs load up on blue spectrum (deep water).

 

if you're going for deeper water corals & inverts i'd opt for the 10000K w/actinics and conversely those closer to the surface should lean toward 6500K w/actinics.

 

edit: like presley says

[LiQuiD]

Try both. I recently bought 2 lighting ballasts with stock 6500k bulbs in them (The Bookworms) and as with my other tanks, wanted to switch the bulbs out for 10,000k/Actinic bulbs. The LFS only had one 50/50-10,000k/Actinic so I grabbed it. Got home, installed it in one ballast and turned it on. It looked nice (better than the very yellow from the 2-6500k bulbs) and like my other tanks was very blue/white. I then turned on the 6500k and it LOOKED GREAT! I would go back and fourth turning off one or the other and realized I liked it best with the mixed spectrum. It looks so much more like natural light like this. So I will not be getting the second bulb and will be leaving it with the mixed spectrum.

 

Basically, as mentioned before, it is mostly personal preference on the bulbs, unless of course you "need" a specific spectrum ie. very deep water coral, get a 20,000k etc. but for the most part, install what you like the best.

 

Go to your LFS and ask them to show you what the different lights look like on. A good LFS will have a show tank with many different bulbs in the hood and usually have them on seperate controllers so they can say "this is all actinic" or "this is with just the 10,000k on" etc.

 

Good luck.

[SteveC]

Originally posted by rocket_155

Have you done a search?

 

If you had then you might have nown that 10,000K is white light and covers the full light spectrum. 6500K is very yellow and covers just the yellow light spectrum

The color temperature is not an indication of the bulb's spectrum. Most bulbs (besides actinics and other specialty bulbs) are "full spectrum" in that they emit wavelengths from red to violet (though not necessarily all of them). But even a 3500K shop light emits blue light. The color temperature is the measure of the overall color of the light emitted when reflected by a white surface: lower color temp bulbs look more red or yellow, higher color temp bulbs look more blue. That's because there is a higher concentration of higher or lower wavelengths depending on the bulb.

 

The measure of how "full" the spectrum is (actually, how well the bulb produces the same wavelengths as the sun) is the Color Rendering Index, CRI. A bulb with CRI of 100 would have all the wavelengths produced by natural sunlight, whereas a bulb with a CRI of 0 would have none of them (obviously such bulbs do not exist). So, a Kitchen & Bath "warm" flourescent will have a CRI in the 70s, and a really good aquarium bulb will have a CRI in the 90s. GE's "AquaRays" Salt & Freshwater bulbs have a CRI in the high 60s, so just throw them away if they came with your hood because they're no better than a cheap shop light, except that they have a much higher color temperature (>9000K). Many freshwater aquarium plants actually look yellow/brown under these lights because they produce so few wavelengths of green. They do produce a lot of blue and red, which is why the AquaRays bulbs look pink.

 

Photosynthesis occurs most efficiently with light in the red and blue ends of the spectrum, so as long as you've got those covered, pick the light that you think looks the best.

 

If you want to know more about lights, I recommend looking at freshwater planted aquaria sites. Those guys have probably forgotten more about lighting than most saltwater people ever knew. Of course, they're shooting for very different parameters (much lower color temp, maximum plant growth with minimal light, etc.) but you get a much better understanding of light since they can't solve all their problems by just putting really bright lights over their tanks.

 

Steve

[Dave ESPI]

Damn Steve... LMAO howd you get a page out of my book ? ? ? ? ?

I JUST was typing that same ###### today ! HAHAHAHAH !

Im going to have to run a trojan scan AGAIN ! Gt out of my computer ! LOL

 

AFAIC, go 6500 and add the actinic. It will ballance nicely.

[SteveC]

Uh oh, a compliment from Dave... This has to mean I'm racking up major flamage karma that's going to come back on me someday.

 

To get a good idea of what the color temperatures actually mean in terms of the quality of light produced, here's a really great table from a photography lighting site. I was going to post it earlier but I couldn't find the bookmark. So when you think about a bulb of a certain color temp, think about the kind of light below filling your tank and you'll have an idea of what it will look like.

 

1000K Candles; oil lamps

2000K Very early sunrise; low effect tungsten lamps

2500K Household light bulbs

3000K Studio lights, photo floods

4000K Clear flashbulbs

5000K Typical daylight; electronic flash

5500K The sun at noon near Kodak's offices :-)

6000K Bright sunshine with clear sky

7000K Slightly overcast sky

8000K Hazy sky

9000K Open shade on clear day

10,000K Heavily overcast sky

11,000K Sunless blue skies

20,000+K Open shade in mountains on a really clear day

 

From http://cybaea.com/photo/color-correction.html

 

Note this is the quality of the light, not the quantity, so even though a heavily overcast sky is darker than bright sunshine with a clear sky, a 10000K bulb will not not look darker than a 6000K bulb. I have a 10000K + Actinic combo and I think it actually looks bright and sunny, but whiter. It captures the "sunless blue skies" aspect of the 11,000K, which is probably the quality of the bulk of the light that reefs receive when the sun is not directly overhead. However, I haven't tried a 6500K yet, so that might look better.

 

I hope this is helpful.

Steve