The main ingredients for photosynthesis are light, carbon dioxide and water. Just as our bodies require certain amounts of nutrients for proper cell division, plants require specific ratios of light for photosynthesis. Plants convert light energy into plant energy in their chloroplasts (much like the mitochondria in human cells). The chloroplasts produce Chlorophyll A and B, the two primary compounds that drive photosynthesis. These compounds absorb primarily blue and red light, more specifically, 439nm, 469n, 642nm and 667nm. LED's allow us to target narrow wavelengths of light to be specificaly tailored to provide the "light" ingredient for photosynthesis. Unlike traditional lighting, such as CFL or HIDs which emit the whole spectral range, all Penetrator grow lights have been scientifically tailored to emit only the spectral wavelengths required for photosynthesis. By dialing into the proper ratios of wavelengths, plants use 95-100% of the light emitted from our Penetrator grow lights, with little to no energy wasted.
At our research lab located at the University of Washington, CFL lighting was compared to our 63W Penetrator with the micromoles emitted by both lights held constant at 430μmol/m2/s2 to find out the effects of spectrum on plant growth. The results were quite amazing! While both lights stimulated growth, the plants under the 126W Penetrator had broader leaf areas, thicker stems and shorter internodal spacing. The Penetrator Series grow lights include 440nm and 470nm blues, 640nm and 660nm reds, 740nm far-red and white with ratios of 5% white, 10% blue and 85% red. Our spectral outputs were formulated based on the relative absorbancy of each wavelength during photosynthesis, and the absorbance peaks for chlorophyll A and B. dd
PAR is the spectral range between 400nm-700nm that plants are able to use for photosynthesis. PAR is expressed in micromoles, which is a measurement of the photosynthetic photon flux density of light, per square meter per second. At Hydro Grow, all light measurements are in PAR because it is the most scientific way of determining a light's ability to drive photosynthesis. While many companies use lumens for their measurements, it is not accurate for plants because lumens corresponds to the human eye's sensitivity for light, which peaks at the green-yellow spectrum.
The amount of light a plant receives, has a direct impact on its growth rate. Most plants tend to grow faster when available light increases, however their maximum growth rate is achieved at a substantially lower amount of sunlight than 2,000 micromoles. The point at which a plant receives more light than they can utilize, is known as the Light Saturation Point. For most plants, the optimum level of PAR lighting is approximately 500 micromoles per square meter (~55 micromoles per square foot), and if these plants receive much over that, they can reach the point of light saturation. In some instances, plants have been observed growing slower when exposed to excess amounts of light, vs growing in their optimal range. For this reason, it is not advisable to supply your plants with more micromoles per meter squared, than what is optimal for their species. Below you will find the light saturation point for several common garden plants, compared to the light output from our LED Grow Lights, and the sun. You can use this graph as a reference for how high to use each of our lights above your crops, depending on what type of plant you are growing.
