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Tom,
A bulb with a color temp of 3000k will also make your frogs and plants appear to be somewhat different colors than what they would be in natural lighting. The 6500k range bulbs render colors much better. I had a tank with 1 4500k and 1 6500k bulb over it. After a couple of months the plants had all leaned toward the side of the tank with the 6500k bulb.
 

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Plant grow lights are actually around the 2700k range with a reddish orange glow. The plants lean to the 6500k because the light is actually a brighter light.
A good light source would be a combination of both types of bulbs. The 2700k causes plants to bloom and flower, the 6500k makes colors more vivid and bright.
 

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you have to think about light intensity. LED's are not very advanced at this point of time, and are really expensive without many advantages against regular fluorescents. It would take almost four of those bulbs to be equivalent to a 26 watt spiral cfl that is half the price. Not to mention that 3000k is very yellow light and not the best for plants
 

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Here's some pics from my foray into LED's (I was trying to reduce the temperature in my terrib tank).
After a month I switched back to my old fluorescents (plus a better fan system) - the LEDs were bright enough, but IMO it was a very 'cold' light and just couldn't compete. The greens looked weird.
The plants looked healthy enough (but it was only a month).
I also had another tank with the old lighting nearby so I always had something to compare it to. Maybe on its own I would have gotten used to it.

Specs from the manufacturer...
Voltage: 18-20
Current: 2A
Wattage:36W
Color temp.:6500
Each LED circuit consist of 6 serial LED voltage 3.2-3.5 +1/8watt 100Ohm resistor protection.
150x6LED in parallel circuit.
 

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Look at the action spectrum (graph B). That tells you how much photosynthesis occurs at a given wavelength.

You can see that the peaks are around 440 and 660 nm (basically red and blue). If a plant receives light at only those two wavelengths from a bulb, you will still observe very positive results.

Regarding color temperature, you are essentially getting an average of the wavelengths from the light source; ie increase blue, increase color temperature.

With an incandescent bulb, color temp is a fine way to estimate photosynthetic activity because the bulb puts out light very evenly across its radiation range.

However, LEDs and florescent bulbs emit with large peaks. This means, for example, a bulb could potentially put out all its light at around 550 nm. This results in a color temperature around 5000k (which seems like a "good" temp to grow). However, in this case nearly zero photosynthesis occurs (verify by looking back to the action spectrum). So, with LEDs and florescent bulbs it is impossible to predict photosynthetic activity unless you are able to find the output spectrum of the bulb.

For instance, if the led bulb under question emits its light with very large peak around 660 and a somewhat smaller peak around 440 it would be nearly ideal for plant growth, all while measuring at 3000k color temp.

Ultimately, unless the manufacture is able to supply output spectrum data, you will just have to experiment with those particular bulbs and hope for success.
 

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looks expensive


Here's some pics from my foray into LED's (I was trying to reduce the temperature in my terrib tank).
After a month I switched back to my old fluorescents (plus a better fan system) - the LEDs were bright enough, but IMO it was a very 'cold' light and just couldn't compete. The greens looked weird.
The plants looked healthy enough (but it was only a month).
I also had another tank with the old lighting nearby so I always had something to compare it to. Maybe on its own I would have gotten used to it.

Specs from the manufacturer...
Voltage: 18-20
Current: 2A
Wattage:36W
Color temp.:6500
Each LED circuit consist of 6 serial LED voltage 3.2-3.5 +1/8watt 100Ohm resistor protection.
150x6LED in parallel circuit.
 

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Look at the action spectrum (graph B). That tells you how much photosynthesis occurs at a given wavelength.

You can see that the peaks are around 440 and 660 nm (basically red and blue). If a plant receives light at only those two wavelengths from a bulb, you will still observe very positive results.

Regarding color temperature, you are essentially getting an average of the wavelengths from the light source; ie increase blue, increase color temperature.

With an incandescent bulb, color temp is a fine way to estimate photosynthetic activity because the bulb puts out light very evenly across its radiation range.

However, LEDs and florescent bulbs emit with large peaks. This means, for example, a bulb could potentially put out all its light at around 550 nm. This results in a color temperature around 5000k (which seems like a "good" temp to grow). However, in this case nearly zero photosynthesis occurs (verify by looking back to the action spectrum). So, with LEDs and florescent bulbs it is impossible to predict photosynthetic activity unless you are able to find the output spectrum of the bulb.

For instance, if the led bulb under question emits its light with very large peak around 660 and a somewhat smaller peak around 440 it would be nearly ideal for plant growth, all while measuring at 3000k color temp.

Ultimately, unless the manufacture is able to supply output spectrum data, you will just have to experiment with those particular bulbs and hope for success.
Well put! i was about to post the same thing with a similar picture, but you beat me to the punch lol. There are few LEDs out there that are ideal for plant growth, but nothing beats a good linear fluorescent bulb though!
 

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I just ordered one of their hoods today for my very tall, 36" high, exo-terra. It is a custom build. I am very excited to see how it comes out. They claim to use LED's of different spectrums for optimal plant growth, which sounds great.
I will report on how it turns out in a few weeks after my build is finished.
 
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