Joined: Mar 29, 2005 Posts: 247 Location: Delhi, India
Posted: Tue Apr 05, 2005 11:39 am Post subject: Light and Photosynthesis
We all know that light is needed for photosynthesis, and while creating an artificial ecosystem, we try our best to mimic the nature; sometimes we even go one step further, by providing the best conditions for a particular organism of interest.
I have recently started growing aquatic plants in my aquariums, and now I am stuck to what kind of light I should use.
Earlier I was using CFLs of gloden yellow glow, but then changed them with cool whites after getting suggestions from A-S-K.
I refreshed school biology on the internet and found that photosynthesis is maximum at 430 and 662 nm. http://www.botany.uwc.ac.za/ecotree/photosynthesis/spectrum.htm
See the graph on this website.
Also surfed through thekrib, learned that pink light does have some good effects on photosynthesis.
Now my query is, Is it wattage or specturm that enhances plant growth or both? I understand that wattage( which in anycase refers to lumens) will decide till what depth, light penetrates in water, for which there is a thumb rule as to so many watts per gal of water.
Increasing brightness beyond that value, does not only increse heat but also lightens the weight from our pockets(electricity consumption is more )
To achieve this, is not a diffiicult task. What is difficult for me is, to attain the right specturm. Is golden yellow, a no no for sure? Is white light good enough( i feel not, please tell me if i am wrong).
Has anyone tried Pink light(Pink light CFLs are available; found that yesteterday only)
How about a combination of Pink and yellow.
According to specturm of visible light, pink should approximately fall near to 430nm and golden yellow (CFL) should cover 662 nm.
Apart from these, CO2 injection is also required, for which I have put DIY CO2 yeast reactor with no CO2diffuser;; only an airstone. My aquariums also have spray bar, which increase agitation, i agree, but I am sure it also increases CO2 pumping from atmosphere.
I am yet to see pearling, though Hornworth(Ceratophyllum) is growing, as I have seen new leaves coming and a branch is also growing!
I learnt that pearling occurs when there is saturation of O2 in water. Saturation will never take place in moving water(spray bar system), am I right? Has anyone experienced pearling with spray bars or agitatted water?
Joined: Jun 29, 2003 Posts: 7084 Location: Bengaluru, India
Posted: Tue Apr 05, 2005 11:58 am Post subject:
White Light, yellow light, Pink Light .... are all subject to one's perceptions. Color temparature is the only accurate thing when it comes to comparing light. Any light from 5000K to 6500 K should be good enough.
Go for triphosphor lamps ( Phillips Tru light 6500K) and you'll have the entire spectrum you need. No need to mix and match.
Increased agitation will drive out CO2 from the water and not "drive - in CO2".
Saturation will never take place in moving water(spray bar system), am I right? Has anyone experienced pearling with spray bars or agitatted water?
Joined: Oct 28, 2004 Posts: 2450 Location: Salem, TN
Posted: Tue Apr 05, 2005 7:36 pm Post subject:
Whats the difference between Philips trulite and aquarium lights assuming wattage and hence the K Value are constant for both?
Also i've seen aquarium lamps in 3 colours viz., pink, white & blue. Is there any difference between the colours wrt K value?
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