[Guest]

I just read an article in a back issue of Reptile magazine where the author recommended 10,000K lighting for the plants in a vivarium. 5500K is closer to the sun at noon, 6500-6700K is the listing for alot of plant lights, so why would you want to use 10,000K? Isn't that more for reef tanks?

 

[FCA]

10,000k is a pretty crisp white light, but not sure how good it would be for plants. It's great for corals though . Normal sunlight is right around 6500K and plant lights are lower than that about 5500K down to 4000k (I think you got those reversed).

 

[Guest]

I might have, but my plant bulbs are 6500. I read this:

1,000 K: oil lamp
2,000 K: tungsten lamp (ordinary household bulb), sunrise and sunset
3,000 K: studio lamps, photofloods, "warm white" fluorescent lamps
4,000 K: clear flashbulbs, blue photofloods, "cool white" fluorescent lamps
5,000 K: blue flashbulbs, electronic flash, average daylight
6,000 K: bright midday sun
7,000 K: lightly overcast sky
8,000 K: hazy sky
10,000 K: heavily overcast sky

If this were true, why would someone want 10,00K for their vivarium if that simulates heavily overcast skies? Unless you were keeping low light plants? The spectrum seems to be almost the same with the 10,000K giving off a tiny bit more blue.

 

[FCA]

I just go by the hydroponic grow bulbs, they are usually around 4300k if I remember correctly. They are usually HPS or MV lamps though.

Remember that this is just measuring the color of the bulb, not the PAR or CRI of it.

 

[bbrock]

I think the problem here is that the term "plant light" can mean a lot of things. Noon day sun on a clear day near the equator is around 5000K - 5500K as Jared reported. Sunlight on an overcast day is more blue and up in the 6500K area. These ratings are only the "color temp" of the bulb. The color temp refers to the color emitted by a piece of platinum heated to a certain temperature. As you heat metal (such as platinum), it turns red first, then orange, then yellow, then white, then blue, etc. so lower color temps tend to "look" more yellowish while higher temps "look" more bluish. The color temp does not really tell you the spectral output of the bulb but it provides a hint. A bulb producing a lot of short wavelenth light is likely to look rather bluish. The color temp is merely an aesthetic choice in vivs. In aquaria it is a little more important because you want a lot of short wavelenght light that has the energy to penetrate water and strike plants and corals with enough intensity to drive photosynthesis. These organisms have adapted to use the short wavelength light found underwater. However, vivarium plants use standard old chlorophyll as their main photosynthetic pigment and chlorophyll reacts to pretty much the full range of visible light except a band in the green wavelengths. That means that any bulb that produces enough intesity of visible light can grow plants. There are some sublte differences in how different wavelength affect other aspects of plant physiology but not probably worth worrying about. As an example, you can grow plants nicely under warm white tubes that I believe are somewhere in the 3500-4500K range and you can grow the same plants just as well with cool white tubes that I think are in the 7000K range. They'll do fine under either. As far as using 10,000K bulbs in a terrestrial vivarium, that seems like a rather stupid recommendation to me. They tend to be more expensive the last I checked, will produce a light farther in the blue range than seems natural for terrestrial systems, and they won't grow plants any better than the 5000-6700K range of bulbs. I don't know for sure but I suspect that the reason many "full spectrum" or UV producing bulbs are in the 6500-6700K range is because they have to crank up the blue end of the spectrum on the bulbs to crank out the UV. My personal preference is for 5000-5500K bulbs but I'm learning to live with the 6500-6700K UVB producing bulbs and the difference is subtle.

 

[Guest]

That was a perfect answer Brent. I wasn't going to mention it but the article was in the March 2004 issue of Reptile magazine titled "Creating a Living Showcase Vivarium." The author was a guy from Vanishing Jewels. The quote from the article was:

Although it is true that dart frogs do not require specialized lighting, the plants and pillow moss in the vivarium do. We recommend power compact fluorescents rated at 10,000K.

Personally I didn't like the tank in the article, they used styrofoam peanuts as a substrate. Just didn't look right to me.

 

[Rain_Frog]

I'm confused here. I personally bought two 13 power compact 10,000 K for my tinctorius 20 gallon high tank. I actually like the effect as it enhances my tincs blue coloration.

I don't know now if 10,000K is bad or what. I am personally going to buy from AHsupply again and thought about buying two 55 watt (one 5000K and one 10,000K bulb) to enhance the colors of the plants and the frogs. I thought about using the blue to enhance my tincs color, while the 5000 K to enhance my tricolors......but will the 10000K HINDER plant growth?

Same goes my clawed frog tank that is 22 inches deep. Should I go with a 10,000 K at that depth, or just a 5500 K? I don't know if freshwater filters out the blue rays like saltwater. Personally, I like 5500 K-6700 as the bluish light for clawed frogs doesn't really bring out their brown coloration.

Whats the color rendering for screw in compact fluorescents?

 

[Dancing frogs]

If I had a lot of time and money, I would try to duplicate the rising sun with several different lights in my tanks. I'd start with the first lights coming on in the morning, probably a low-intensity lower K light, then later, have a 5000k turn on, then add a 10000k for the midday hours(all bulbs on). It would take a lot of experimenting and buying lots of different bulbs to get a good effect.
Just an idea I thought I'd share with y'all!

 

[bbrock]

I'm confused here. I personally bought two 13 power compact 10,000 K for my tinctorius 20 gallon high tank. I actually like the effect as it enhances my tincs blue coloration.

I don't know now if 10,000K is bad or what.

If you like the look of the 10,000K, then there is no harm in using it. It is a purely aesthetic choice. The plants will do fine. What you see as "color enhancement", I see as "color distortion" which is a purely personal choice so it's best to do what you like best. It's just like many so-called plant lights are really just regular flourescent bulbs that have been tweaked to exagerate the colors of flowers. Some people like the effect, others don't.