Not liking 10,000K MH bulbs
- Thread starter dkedrowitsch
- Start date
Hey guys!
This article prompted me to bring this thread back from the dead, as it supports some of the arguments that DaisyPolyp and I made in regards the proper lighting spectrum for photosynthetic inverts.
http://www.advancedaquarist.com/issues/ ... eature.htm
This article prompted me to bring this thread back from the dead, as it supports some of the arguments that DaisyPolyp and I made in regards the proper lighting spectrum for photosynthetic inverts.
http://www.advancedaquarist.com/issues/ ... eature.htm
reefnutz":7zvy5h20 said:
any mh from 6500 k and up is just fine for any coral's health and growth
the rest is window dressing and personal preference re: the color of the light to your eye, and the color pigments the corals will 'shift' to.
a brown pigmented acropora under one mh, that turns blue under another is no less healthy, under either bulb
once you get to 6500 k and higher, there's plenty of par available for corals
i actually preffered the 6500k bulbs mixed w/10 k's, and my softies and lps grew like weeds under regular coralife 6500's
pigment change says nothing about coral happiness, imo- it's just a reflection of the coral adapting to use whichever spectral range bulb yer usin more efficiently , and may even be the result of the coral's attempt to screen out light, much the way we use sunblock,and tanning lotion, iirc :wink:
I read Sanjays most recent article over the weekend, and the he says that it's still pretty much open for debate if there is a "proper" spectrum for this or that coral. There's ongoing research. So nobody can say that a certain spectrum is best, at least not with any degree of research or empirical data behind them.
Although I respect your opinion Reefnutz.
If you end up being right, I'll send you a beer OK? :lol:
Jim
Although I respect your opinion Reefnutz.
If you end up being right, I'll send you a beer OK? :lol:
Jim
Thanks for jumping back into the fray, Chris.
In seems to support my opinion unless I misinterpreted it. The 400 watt 6500K bulb used in the experiment caused photoinhibition and stress to the coral even during the low inensity levels during warmup.
The 6500K closely mimics the midday sun spectrum and furthur supports the Photosynthesis on coral varies throughout the day study by the University of Technology Sydney that I included earlier in this thread. In addition, possibly supporting why photosynthetic rates are at its highest during the early morning and late afternoon when the spectrum has a much higher kelvin rating.
In seems to support my opinion unless I misinterpreted it. The 400 watt 6500K bulb used in the experiment caused photoinhibition and stress to the coral even during the low inensity levels during warmup.
The 6500K closely mimics the midday sun spectrum and furthur supports the Photosynthesis on coral varies throughout the day study by the University of Technology Sydney that I included earlier in this thread. In addition, possibly supporting why photosynthetic rates are at its highest during the early morning and late afternoon when the spectrum has a much higher kelvin rating.
I agree that the study supports the point you have raised in the past that too much PAR can inhibit photosynthetic activity in corals. I'm still not sure I see the tie to spectrum though. These studies appear to be analyzing the relationship between photoinhibition and intensity, not necessarily spectrum.
If a 400 watt 20000K lamp was used in the study and produced similar PAR levels, the results may very well have been the same, no?
Another thought - if you were getting too much light from the 400 watt 6500K lamp, couldn't you just as easily drop back to say a 250 watt 6500K lamp to get under the photoinhibition levels of PAR? Wouldn't that be more economical than using a comparable higher kelvin lamp (ie. a 400 watt 20000K lamp) to achieve the lower PAR levels (although, granted, it would not be as aesthetically pleasing )?
If a 400 watt 20000K lamp was used in the study and produced similar PAR levels, the results may very well have been the same, no?
Another thought - if you were getting too much light from the 400 watt 6500K lamp, couldn't you just as easily drop back to say a 250 watt 6500K lamp to get under the photoinhibition levels of PAR? Wouldn't that be more economical than using a comparable higher kelvin lamp (ie. a 400 watt 20000K lamp) to achieve the lower PAR levels (although, granted, it would not be as aesthetically pleasing
)?ChrisRD":3rj2dx0n said:Another thought - if you were getting too much light from the 400 watt 6500K lamp, couldn't you just as easily drop back to say a 250 watt 6500K lamp to get under the photoinhibition levels of PAR? Wouldn't that be more economical than using a comparable higher kelvin lamp (ie. a 400 watt 20000K lamp) to achieve the lower PAR levels (although, granted, it would not be as aesthetically pleasing
That would be the logical approach. Still, the distress occurs even at 260 µmol·m2·sec which is well within the output of a 250 watt bulb. I can't help but believe this wouldn't be the case under a bluer spectrum bulb.
Perhaps I could inquire if Dana Riddle could run ETR, qP, and NQP tests under 10K, 14K, or 20K bulbs.
:? Like Jim mentioned, we're still far from the answer.
Not to drag this back from the dead yet again, but for those that may turn it up in a search some day...
This article by Richard Harker Shedding Light On The Reef reminded me of this thread. Particularly the section on "Light Quality".
Many thanks to KevD1 for resurrecting the old Aquarium Frontiers articles. Lots of good information there...
This article by Richard Harker Shedding Light On The Reef reminded me of this thread.
Particularly the section on "Light Quality".Many thanks to KevD1 for resurrecting the old Aquarium Frontiers articles. Lots of good information there...
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