# do I need to replace 12000K bulbs?



## bigstick120 (May 23, 2005)

Sadly, Yes you need to replace the light, plants absorb light from about 5,000-10,000K. So those light wont do much for your plants. Here is a place with some nice bulbs fairly cheap
Here


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## lifetapestry (Jan 12, 2006)

I've been using the 50/50 bulb that my 96 watt coralife fixture came with for about eight months now. I also have 2 15 watt 6700 fixtures on my 55 gallon tank. I keep intending to replace the bulb, but I actually like the way it colors the fish and the plants.

I get good growth, don't have algae, and am generally happy with my setup. My suggestion to you is that you try the bulbs as they are, see if you like the color and the plant growth, and then switch if you're not happy. Some actinic bulbs make the aquarium look eerie and weird, while others do not. 

If you do some googling around the web related to actinic bulbs and freshwater aquariums, you'll see that at other reputable places, actinic bulbs are not considered worthless for plants. I think it's not that they produce no useable light for plants, but *less* light for plants. How much less light, I'm not sure. My understanding is that the Kelvin rating on bulbs indicates the average wavelength produced by that bulb, not the only wavelength. Thus, an actinic bulb will produce some light in the 5700-10,000 range that the plants can use-- how much probably depends on the specific brand of lightbulb.

Bottom line to me, from my experience and reading, is that actinic bulbs (especially when combined with the more traditional freshwater bulbs, which you have) can work fine. Your plants will definitely get more light with only 5700-10,000 K bulbs, but the setup you have may work well for your goals. Only way to know is to try it, then replace the bulbs if you're not happy with the look or the plant growth.

Karla


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## attack11 (May 5, 2006)

someone needs to make a sticky thread on this subject.

actinic is a 400-500nm bulb (blue). it covers half of the kind of light plants need, so it'll work but not exceptionally well. the 12000k is probably marine oriented so it'll also have a big 400-500nm peak and probably trail off somewhere around 600nm, but not in a good way.

plants need 400-500nm and 600-700nm wavelengths.

i'm growing plants with an 18000k bulb designed for plants on my lowtech tank. kelvin is what you see, not what plants use.


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## abc (May 18, 2004)

so let me understand what everyone is saying:

the bulb ideal is 5400k-6700k and while kelvin is what I see, it also tells me that the bulb uses wavelengths that are optimal for plant growth

by using the actinic and 12000k bulbs, they will help plant growth, but not ideally. The question is how non-ideal are they? Is there enough there to keep my plant growth going? It would be nice to figure out beforehand whether the set up will work but I guess the only way to do it is to try, especially since I'm on budget.

Thanks for the link for cheap replacement lights. For experiment's sake, I'll try the current set up and post later how my plants are doing. I think I'll eventually replace them for comparison's sake, but when I can afford it.

I'll keep this thread updated.

abc


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## abc (May 18, 2004)

Oh yah, the link above is for a 55W compact flash bulb. So can I replace the 65W with 55W? I don't want to start a fire with my new lights but I'm not sure if mixes wattages is OK


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## attack11 (May 5, 2006)

well, if the par from the bulbs is good enough; the (probable) lack of proper wavelengths can be offset enough that you won't have hindered growth. i've been able to grow monsters in my planted tank with a marine 10000k bulb.


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## attack11 (May 5, 2006)

oh, btw actinics are technically pure par; but only half of what you need.


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## bigstick120 (May 23, 2005)

55/65 watt bulbs are the same thing, the ballast is what will drive your bulbs


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## abc (May 18, 2004)

thanks for the clarification!


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## Vafik (Mar 15, 2005)

I too use a 50/50 on one of my tanks b/c it makes the colors in my fish pop. And I too have heard that it would do little to no good for my plants but they dont seem to mind


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