Re: [Aroid-l] LED lighting (was aroid recommendations)

From: ExoticRainforest <Steve at ExoticRainforest.com> on 2009.01.23 at 21:51:14 I'm sure not trying to promote anybrand and I'm sure Bonaventure's choice is excellent.  But let meintroduce you to another alternative which is relatively inexpensivefor aquarium plant use.  These units are called Power Compact lights. They normally consist of two bulbs in a nice looking light system thateasily mounts on almost any size aquarium.  The bulbs are normallyaround 130 watts which means two bulbs will give you about 260 watts ofpower.  That would amount to approximately medium intensity sunlight. These are commonly used for growing soft corals which require a strongintensity light.  If you use two systems at the same time you can get ahigh enough intensity to grow stony corals which are even harder togrow.  The bulbs can be ordered in daylight (around 5500 degreesKelvin) which is the same as sunlight or in higher Kelvin values forplants that normally grow in the understory where the light is a bitbluer.  I've grown living corals for much of the last 17 years and havefound these work great and I promise corals are harder to keep alivethan plants. I'm not trying to push any seller but just look up Power CompactAquarium lights on eBay and see who has the best system for the bestprice.  Be sure and specify the color (Kelvin value) of the bulbs youwant to receive if you choose to order.  If you buy these in a localaquarium store you'll pay at least double the price for the same lights. Steve Lucas www.ExoticRainforest.com Steve Marak wrote: Hi Bonaventure,PAR is just the acronym for "photosynthetically active radiation", i.e., that in the frequency ranges which plants actually use (400-700 nm or so).Since LEDs are by nature monochromatic (the "white" ones either use multiple colors together, or have a phosphor which re-emits broader spectrum light), plant growers very quickly hit on the idea of using only LEDs which emit near the peak absorption frequencies of the two higher plant chlorophylls (430-455 nm in the blue, 640-665 in the red).It's not clear to me whether that really improves things or not, since my understanding was that other pigments present in leaves, acting with chlorophyll, tended to spread out the range of frequencies which plants could use across that 400-700 nm range. So I bought a PAR meter, even though it wasn't cheap and it uses funky non-SI units (microeinsteins, or often microeinsteins/meter squared/second) that have to be converted to and from *everything*.I don't know if I've really learned much or not (except that in the end, you still have to just try things and see if the plants grow well), but I can sling a lot more numbers now when I talk about it!SteveOn Fri, 23 Jan 2009, bonaventure@optonline.net wrote: --------------010403070604040309030807

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