12-05-2010, 03:28 PM
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Originally Posted by Byron
I actually use a combo, but didn't want to confuse further since he already intends to retain one of the others. On my 115 it is a 6700K Life-Glo 2 and a 11000K Lightning Rod Super Daylight. On the 90g a Life-Glo 2 6700K and a ZooMed Coral Sun which is high in blue and from colour appearance must be around 10000K. On the 70g I have a Life-Glo 2 6700K and a Phillips Deluxe Daylight which is a cool white.
I remember your (Mikaila) mentioning elsewhere about using high-tech to propagate your plants to sell. You might want to consider a combo similar to what I've mentioned. In an article in the July 1987 issue of FAMA, K. Richards reported a study of various spectrums of light with the identical plants (Elodea) and conditions; plants grew strongest (producing more oxygen) under a combo of full spectrum and cool white; second under cool white alone; third under full spectrum alone; fourth under warm white alone. This study is cited in Diana Walstad's book Ecology of the Planted Aquarium, with the graph (p. 180). The plants produced 47ml of oxygen in each 24 hour period under the combo compared to 38ml under cool white, and 25 ml under Vita-Lite (which is the red/blue designed for plants).
I can't use a combo unless they start making single combo lights like that similar to the 50/50 bulbs. These bulbs I really like and were recommended on a plant board. There is actually a sticky dedicated just to them. I do need new ones. Have never replaced my bulbs and I can tell they are starting to wear out. As far as their spectrum, the color spectrum for the bulb is actually on the box and they peak in red and blue with very little green peak. I use to use the "full spectrum" and still do on half of my tanks. Sometimes though it causes a very green look to the tank, like everything is washed over in green and I really didn't like that. I would prefer to use a combo of 6700K or 7000K along with these bulbs, but the 9325K only comes in T8s or 55 watt power compacts. My main tanks only run 1 or 2 bulbs and PC are not the same length of the tank, so one side would be one temp and the otherside would be the other temp. If plants grow best under a combo of full spectrum and cool blue wouldn't it just work best if you used a single bulb around 7500-8500K? I also thought that color temp alone only vaguely refers to the actual color spectrum of the bulb...
The bulbs I use have this reported spectrum on the packaging, as I said they are also reported to be 9325K. But it is not believed they truly are, estimated to be around 8000-9000K.