northerntights
Well-Known Member
Ok so I have been doing some research into PAR or Photosynthetically Active Radiation and what this corresponds to. To my dismay I found that this measurement is practically useless. After talking with a plant physiologist at my college it turns out that this measurement is simply the amount of light from 400 to 700 nanometers in wavelength or blue to red light. It does not, in any way, correspond to the sensitivity of chlorophyll to WHAT specific wavelengths. In other words you can have a powerful light giving off nothing but green light, a practically useless light, and it's PAR rating may be that of a hortilux blue full spectrum bulb! Although it IS a standard rating system, it has been misused by lighting companies to sell bulbs at higher prices.
However, if you find a company using PUR units, or Photosynthetically Usable Radiation, you will have a much better idea of what your getting... however, this system is not an industry standard and does not make the products look as good to the consumer and thus it is rarely used. Much of the issues involved in creating a true PUR standard stem from the different wavelengths of light that different plants use. Many species of plants have karatinoids, chemicals that can absorb green light. However, as in many plants, marijuana lacks this in any significant quantity (hence why the leaves turn yellow when they die and not red as some trees do).
I thought this would be important to share with others on this site, many people are mislead by this measurement and it's time it stopped.
However, if you find a company using PUR units, or Photosynthetically Usable Radiation, you will have a much better idea of what your getting... however, this system is not an industry standard and does not make the products look as good to the consumer and thus it is rarely used. Much of the issues involved in creating a true PUR standard stem from the different wavelengths of light that different plants use. Many species of plants have karatinoids, chemicals that can absorb green light. However, as in many plants, marijuana lacks this in any significant quantity (hence why the leaves turn yellow when they die and not red as some trees do).
I thought this would be important to share with others on this site, many people are mislead by this measurement and it's time it stopped.