10,000K bulbs

[Discomafia]

I want to get the whiteish look that 10,000K flourescent bulbs give off... However, are 10,000K bulbs solely an aquarium hobby thing, or can I get them at Home Depot or something like that. I can get daylight (6700K) and plant (2700K) bulbs but I've never seen anything with higher kelvin rating than the daylight tubes they sell in Home Depot. Also, can T10 or T8 bulbs fit in a T12 socket, or are any of these bulbs with diff. diameter sizes reversible in any way? Diff. bulbs fitting in diff. sockets I mean... Thanks for any info!

 

[guppygirl]

Hmmm.... I would think that the 10,000K would be aquarium. You could search on the website for home depot too. I don't think you can exchange different sizes for the sockets however.
HTH!
Robin

 

[Aulonochromis]

You'll have to get aquarium bulbs for 10,000k. You won't find anything higher than 6500k at Home Depot. The T8 and T10 bulbs will fit in T12 sockets, but they may not light up depending on the type of ballast. T8 bulbs require an electronic ballast designed for T8s to work properly. I got my electronic ballasts from Home Depot for about $25.

 

[spsigps]

10,000k lights are used for marine tanks. If yours is a planted tank, the better choices wold be 6500k or 8000k. Anything inbetween would be fine too.

6500k (tinge of yellow) simulates overcast sky, 8000k simulates white sky and 10000k simulates clear bright sky (tinge of blue).

10000k is not totally unusable for planted tanks, just not as effective as the lower k lights.

 

[Lateral Line]

For a planted tank, your best choice of lamps is between 5000K and 6700K. Higher then that and the chlorophyl absorption band at the red end of the spectrum is not covered, lower, and the blue absorption is not covered.

In addition, I thing the 2700K lamps often sold as "plant" lamps make the tank look dim and dingy.

 

[Silly me]

6500k (tinge of yellow) simulates overcast sky, 8000k simulates white sky and 10000k simulates clear bright sky (tinge of blue).

personaly anything over 6400K looks blue to me..

sunlight is 5500K add some blue sky and 6500K what your looking at..

the krib does have a very nice write up about light..
http/www.thekrib.com/Plants/Tech/

 

[Discomafia]

Thanks for all the replies guys! I'm currently running two 30W, 6700K bulbs in my tank now which gives me around 1.8 wpg. I know that CO2 doesn't make a diff. unless I have 2 wpg and plus, my water is really soft and acidic, so I'd rather not add CO2 for fear of ph swings.

The only reason I want the 10,000K bulbs is because I want that bright white look those bulbs give off. My 6700K bulbs still give off a yellow tinge, and I don't really want that. I already know that the best spectrum, for plant growth anyways, is 5000 to 6700K, but I think that intensity is more important than the kelvin rating. I used to use two 25 watt compact flourescent bulbs that were 2700K and I got good plant growth in my old 10 gal.

Also, does the wpg rule only apply to flourescent bulbs in the 5000-6700K range or ....?

 

[Nospherith]

From thekrib.com:

The key is the "blend" of spectral spikes
they use to achieve the appearance of "whiteness". They aren't continual
spectrum- types of lamps, but cluster their output at specific wavelengths,
and if you vary the wavelength and intensity the combination shows  varying
degrees of "white". -D.A. Youngker

Kelvin rating may not be as important as the light output at specific wavelengths of the light spectrum that are beneficial to plant growth. Sure, Kelving rating for light bulbs is based on the color emitted by a metal at degrees K, but nowadays manufacturers make their lights specific to plants and can manipulate the light to spike at certain wavelengths.

It seems as though there is disdain for the validity of 10,000K bulbs for freshwater planted aquaria. Based on the importance of the wavelength spikes, 10,000K bulbs aren't all that bad. (Probably not the best but they work).

Case in point:

...If you can compare the two, look for the one that puts out the highest combination of
420-440 nm and 610-660 nm - the blue and red portions. -D.A. Youngker

This is the spectral chart for my 55w 9,800K bulb. This isn't the first time that I've heard that spikes at the 420-440 nm and 610-660 nm wavelengths are optimal for plant growth. My light is 9,800K and it seems to have the spikes in the right place. The light output looks a natural white, it looks great over the aquarium and the plants, and algae unfortunately, are growing great.

Granted I haven't actually tried 6700K bulbs becuase this 9800 is the one that the hood came with but I'll probably end up replacing it with a 6,700K sometime down the road. So all this stuff is me putting two and two together not verified.

Also, does the wpg rule only apply to flourescent bulbs in the 5000-6700K range or ....?

That's a good question. My guess would be that it's more a matter of intensity. The K rating's effect on plant growth may be important, but probably marginal on the intensity (wpg). For instance, a 36watt 6700k bulb over a 10g might be 3.6 wpg, but if it were a 10,000k bulb it might be something like 3.2 wpg. Not sure, just a guess.

 

[Discomafia]

Yea, I remember reading someone posting about his tank and the 10,000K bulbs he used, and the plants weren't doing too bad... Must have been you Nospherith.

I've seen a few tanks entered in the AGA 2004 Aquascaping Contest that used 10,000K bulbs alone, or combined them with 6,700K bulbs. Since I saw their tanks in the contest, this proves that 10,000K bulbs are not totally unsuitable for FW planted tanks.

However, as stated already, I'm in this for the look of the light, as the 6700K bulbs I have produce a yellow tint and I want a whiter colour.

 

[Angry_Platy]

I have dual 6500K/10000K bulbs, I have only had plants 12 days so far and they are all growing like weeds with CO2 of 25ppm.....

 

[Discomafia]

Before I got my current light setup, I was seeing some good vertical growth by my h.polysperma and r.indica when I only had a 25w AquaGlo in there. It's 18,000K. And I thought that intensity was more imp. than the kelvin rating, but there was nothing going right for the plants yet... What sort of plants do you have in there now Angry_Platy? I'm planning on fitting the old 25Wlight fixture into my canopy and use that as well. Will have to experiment w/ the bulb, but now that'll mean I'll now have nearly 2.6wpg, just have to figure out how to get my GH up so that I can get some DIY CO2 in there!

 

[George Farmer]

I heard of success stories with 10000K. Personally I like a mix of colour temps, then hopefully all the relevant wavelengths are available and the display gives a decent balanced colour to the eye. I use 3000K (warm, yellow/orangey), 6700K (white) and 7500K (greenish with a hint of blue), the overall effect is very pleasing to the eye and the plants love it too!

 

[Lateral Line]

does the wpg rule only apply to flourescent bulbs in the 5000-6700K range

I've posted the absorption spectra for a and b chlorophyll several times. Plants use chlorophyll to convert light, (+other things of course), into more plant. To get optimum plant growth, you should target the absorption bands that chlorophyl is active.

If you have 10 wpg and all of the light is outside the active bands for chlorophyl, as far as the plant is concerned, the light is not there.

Lamps most suited for a planted tank are full spectrum, 5000K - 6700K lamps. A lamp matching that spec will not have a very peaky spectrum, rather a broad spectral distribution most like natural light. The braod spectrum also raises the CRI value, a high CRI value makes colours looks natural. CRI's over 90 are good for aquaria.

The "wpg rule" is not a rule, just a guideline. It applies to tanks of common sizes and regular shape. Smaller tanks tend to require more wpg then larger tanks. Deep, and especially hex type tanks require a lot more. The wpg rule is a way of combining surface area and depth into an easy to understand/quote sound-bite.