High Output Compact Fluorescent Lights?

[Tin Pusher]

I am using the new "High Output Compact Fluorescent Lights" for my 50 gal. They are 110W and are 9325 degrees kelvin. My plant books talk about using around 5000 degrees kelvin and that 6000 produces long spindly plants. Has anyone have experience with these lights or lights with a kelvin temperature this high?
Thanks

[ronrca]

The kelvin of the sun at mid day is 5500K! That is correct! I do not have too much experience with K factors over 6500K but as far as I know from other peoples experience, 6500K is around the max you should go. 10000k usually is for reefs I hear!

How are your plants doing? If they are donig fine, leave it be!
I would imagine you are getting a very quick growth rate! Any C02?

[gj555]

I have been reading the plant dedicated forums on other non-discus plant only sites and it appears that these 9325k lights are becoming more and more popular. GM makes the regular fluorescent version and calls the aquarays. Many people swear by the success they have with them. I have the compact fluorescent version of them (also from GM) which comes with the All Glass 110 watts cf lights. They have high lumens rating which is supposed to be really good for growing plants and more important than how many k they have or the CRI. My plants are fine (pics are here: http://forum.simplydiscus.com//index...;threadid=4081)

New cf replacement lights are expensive in canada so I use whatever they came with. I having been reading more and more complaints about 5000k lighting looking too yellow, so the 9325k lights are a refreshing change. But, I also find the 9325k lights a little too purple. One thing you can do is to take a regular t12 or t8 fluorescent light strip in the 3000k to 5000k range and add it to your tank to even out the color.

[ronrca]

You bring up a good point! 5000K does seem a bit yellow. Raising the color temperature can help with getting a brighter color for sure. It is a very good idea to mix the lamps up instead of just going with 1 lamp.

However, it is true the lumen rating is much more important as this indicates the amount of light the lamp is producing (actually lux would be the best measurement). Plant growth should increase (more light, more photosynthesis, more growth providing nutrients have been meant).

However, the color temperature (k) rating is imo way over rated. Usually these lamps cost a fair chunk compared to 5500k and imo, the cost does not offset the growth and is not worth it. The same goes for the CRI, the higher the CRI value, the truer will be the colors seen this light. Interestingly enough, incandescent lamps have one of the highest CRI valves (97) and a full sprectrum fluorescent 7500K valve is 94.