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Re: LED lighting (was aroid recommendations)

  • Subject: Re: LED lighting (was aroid recommendations)
  • From: ExoticRainforest <Steve@exoticrainforest.com>
  • Date: Fri, 23 Jan 2009 15:51:14 -0600

I'm sure not trying to promote any brand and I'm sure Bonaventure's choice is excellent.  But let me introduce you to another alternative which is relatively inexpensive for aquarium plant use.  These units are called Power Compact lights.  They normally consist of two bulbs in a nice looking light system that easily mounts on almost any size aquarium.  The bulbs are normally around 130 watts which means two bulbs will give you about 260 watts of power.  That would amount to approximately medium intensity sunlight.  These are commonly used for growing soft corals which require a strong intensity light.  If you use two systems at the same time you can get a high enough intensity to grow stony corals which are even harder to grow.  The bulbs can be ordered in daylight (around 5500 degrees Kelvin) which is the same as sunlight or in higher Kelvin values for plants that normally grow in the understory where the light is a bit bluer.  I've grown living corals for much of the last 17 years and have found these work great and I promise corals are harder to keep alive than plants.

I'm not trying to push any seller but just look up Power Compact Aquarium lights on eBay and see who has the best system for the best price.  Be sure and specify the color (Kelvin value) of the bulbs you want to receive if you choose to order.  If you buy these in a local aquarium store you'll pay at least double the price for the same lights.

Steve Lucas

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!


On Fri, 23 Jan 2009, bonaventure@optonline.net wrote:


fn:Steve  Lucas

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