[Revan]

Riporto un articolo molto interessante riguardo alle frequenze luminose ed all'illuminazione degli acquari tratto dal sito:
http://www.dec.ctu.edu.vn/cdrom/cd6/.../lighting.html

Quote:

Light frequency / distribution by uweb@PROBLEM_WITH_INEWS_GATEWAY_FILE (Uwe_Behle) Date: Mon, 16 Aug 1993 I just re-read an article in the DATZ (a German magazine for aquarists) dating August 1993. There is some information on light colour that goes into the same direction as my earlier posting. 1) Some 20 years ago a guy named McCree found out that certain algae have two sensitivity peaks for photosynthesis. One is in the red part and one in the blue part of the spectrum. The old statement that red light produces thin long-stretched leaves and blue light short growth dates from that time. McCree's results were taken to be valid for higher plants as well. This proved to be wrong. 2) When McCree did some experiments of the same kind with higher plants, he found indeed totally different data. The big peak is now at 6200nm (red), the sensitivity curve then drops of to 50% for colours between 4000nm (green-blue). I am sure you have seen this curve in several books on plants. This is the reason that (most) plants look green. 3) Dr. O. Elgersma (Philips) generated this curve from McCree's results. It is the average sensitivity based on many of the experiments McCree did. 4) In 1982 Philips Corp. did a lot of experiments in order to find out the effects of different light colours on aquarium plants. The following plants were used (because of their fast growth): Hottonia inflata Limnophilia sessiflora Ludwigia natans Bacopa amplexicaulis Hygrophilia polysperma Rotala macandra The surprising results were that the influence of colour was less than 10 percent! 5) The results are applicable for all aquatic plants because all aquatic plants contain the same type of chlorophylls as the land-based plants. Algae contain additional chlorophylls that are not found in higher plants. From McCree's experiments it is obvious that these additional chlorophylls are responsible for the sensitivity to blue light. Bottom line: ============ It does not matter what colour of light you provide for your aquarium plants. Choose a colour that makes it look good for you. If you are not interested in algae (fresh water people usually are not) you can additionally try to avoid the blue part of the spectrum (or keep it to a minimum). This also means that high light temperatures (>5500K or so) are better suited for a salt water aquarium. ---> Your mileage may vary.<--- The September issue of DATZ will address the question "Is there a special aquarium light?". It will be interesting to see what their answer is. Uwe -- NAME Uwe Behle, HP Boeblingen Instruments Division EMAIL uweb@hpbbn.bbn.hp.com (internet)\ df3du@db0sao.ampr.org (packet radio) SNAIL Hewlett-Packard GmbH, BID R&D, Herrenberger Str. 130,\ D034 Boeblingen, Germany PHONE 01131-142016 (work) FAX 01131-143883 (work)