right wavelength vs more watts

[hashbaz]

I didn't want to spend the money needed for 3 watts per gallon. Instead I bought bulbs whose wavelength output very closely matches the best absorbed wavelengths for chlorophyll A. I'm thinking better light instead of more light.

I'm not a biologist and don't know for sure if this will work. Do the plants need more light at other wavelengths? (possibly for pigments other than chlorophyll A) I'm guessing that this setup is great for most green plants but poor for red plants.

There are a lot of advantages to this kind of setup: The light is not blinding to me or the poor fish who live under it. It costs less to buy and less to run. And it makes less heat. I just hope it will do as good for the plants as I think it will.

nitty-gritty boring details:

the wavelength vs power for my bulbs is found at: http://www.hagen.com/usa/aquatic/product.cfm?CAT=1&SUBCAT=112&PROD_ID=01015830021001

the absorption vs wavelength rates for chlorophyll and other pigments:
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookPS.html

I now have 40 watts for 29 gallons (1.4 watts per gallon). The plants I have are anacharis, hornwort, java fern, and two unidentified plants. These aren't very good plants to test my theory so I hope to buy some that are supposed to need more light.

What do you guys think of my theory?

 

[medge00]

IME, more watts is more important. even if its the best kind of wave, if there isn't much getting there, it doesn't do much good.

 

[vega]

Good wavelenght probabily is better for plant but you also have to consider the power need by the light to penetrate/travel throught the water. And the power itself is in Watt.

For norm ppl like most of us, to calculate the relativity of wavelenght, power, water dept due to reflection is way out of our capabilities.

I tried to look into it last time but half way through the textbook i just lost my way... :|

Probabily you can look into the whole thing and come out with a calcution program. I ll definately appreciate it.

HTH

 

[Endgame319]

The plants you have now will be fine in your currnet light, but I'm not too sure about higher light plants.

 

[malkore]

Vega,
I just want to clarify this: a watt is the measure of electricity CONSUMED by the bulb. The actual measure of light output is lumens. ordinary screw-in incandescents have a poor watt to lumens ratio. The 'watts per gallon' rule is based on the watts to lumens ratio for normal output fluorescent bulbs.
compact fluorscents have an even better watts to lumens ratio.

metal halide is less efficient than normal fluorescents, but because you get so much light from a single bulb, they have a place in the hobby.

Everything else stated is true: you do need a bulb with an adequate wavelength/spectrum for plants, but without proper intensity, the plants won't make it.

Best of luck!