Lighting

[Greenfingeredste]

Hey guys...another beginner question here. As I have stated I have a number of boo seedlings that I will bring indoors over winter until I can plant them out next spring. I have decided to invest a small amount in a full spectrum led light panel. This one http://www.ebay.co.uk/itm/181756086178? ... EBIDX%3AIT I was wondering will this be adequate light or will I need more?

[Nicholas]

It is difficult to tell as the light intensity will obviously depend on the distance you place it to your seedlings.

When I use the output of lumens from your lamp (I went with 1800, 8 lumens per individual LED) shining it on an area of around 13 square cm would receive roughly the same amount of light as on a sunny day.
Lumens are not an ideal measurement in this case as they relate to visible light and not the wavelengths used for photosynthesis.

Obviously you won't need full sunlight equivalence to get your seedlings over the winter so the 13 square cm is only an example that one can relate to.
Don't forget that doubling the distance to the light will leave you with one fourth of the the intensity.

[Greenfingeredste]

Thank you for reply. This is the info about light wavelengths


LED Grow light has 225 high powered LEDs that draw 14 Watts of power to nurture your plants with red and blue illumination that will boost their photosynthesis increasing growth and yield.

The Excelvan PG01 LED grow light will emit light in the red and blue wavelengths at 620-630nm and 460 to 470nm, these wavelengths correspond to chlorophyll's absorption peaks and will greatly enhance the photosynthesis of your plants. This LED plant light uses just 14 Watts of power and generates very little heat so unlike regular light bulbs, HID lamps or fluorescent tubes which means you can enjoy large savings on your power bill. With a 50,000 hours life span this LED grow panel comes with 4 strong wires and hook for easy, secure installation making it ideal for your greenhouse or living room. With this grow lamp you don't need to have green fingers so it’s easy to start your own warm house or plant farm today and earn big buck from fantastic flowers, vegetables and plants.

[foxd]

I tried a few of the LED panels and was not impressed. They didn't seem to supply enough light and the reliability left a lot to be desired. (LEDs are in series, any one failing took out a string of lights, and the failure rate of the LEDs was awfully high.)

[johnw]

Heliospectra has recently been trialed at the Goteborg Botanic Garden with incredible results. And that was with the most challenging alpine plants that demand incredible light to stay compact and true to form. I'd have it if I could afford one let alone a pair.

http://www.heliospectra.com/reviews

johnw

[Greenfingeredste]

Thanks all for reply's. I guess I will buy it tomoz and give it a go...it carnt do any harm. I am hoping that if I can get distance correct and the time light is on it will stimulate new growth in the Boo's throughout the winter(but I doubt it). I will post some pic's of set up once it has arrived and I have it installed

[Nicholas]

Heliospectra has recently been trialed at the Goteborg Botanic Garden with incredible results. And that was with the most challenging alpine plants that demand incredible light to stay compact and true to form. I'd have it if I could afford one let alone a pair.

johnw

I'm generally the sceptical type, it just feels like too much of a sales pitch.
Not that I don't think that LED lights with the proper spectrum can be tremendously effective and energy efficient, but at that price point the question arises if it is economical.

One of the whitepapers they link to on their site (http://journals.plos.org/plosone/articl ... ne.0099010) appears to indicate that LED is still more expensive (over a five year span) than HPS and a lot of that has to do with the initial investment cost, which is a lot higher for this type of LED fixture.

[johnw]

Nicholas - I can say nothing about whether or not it's economical. I am looking to replace sodium halides, they give off too much heat and pose a danger where they are and would love to get a pair of these.

Scottish plantsman friend was in Goteborg and saw the Dionysias, said they were faultless, best they'd ever seen. The growers at GBG, some of the best in world, were very enthuisiastic with the system. None of that is based on Helio's sales pitch. I understand some other BGs are looking into supplemental winter lighting with them. I priced them out and think they were between $2000 & $3000 per set so one would expect professional results.

Have a read - http://www.srgc.org.uk/logs/logdir/2014 ... G_4614.pdf

john

[Greenfingeredste]

That's some impressive lighting system.....Wish I could afford that lol...Maybe when I win lottery