Below are the spectral distribution charts of two HORTILUX grow lamps with very different spectrums – the HORTILUX BLUE Metal Halide and the HORTILUX Standard Metal Halide. When the charts are compared side by side, the difference in the quality of the two spectrums becomes readily apparent. The BLUE delivers a broad, full spectrum for your plants whereas the Standard Metal Halide provides a spectrum full of peaks and valleys and areas of lower spectral output.
When comparing those two spectrums many would guess the HORTILUX BLUE has more PAR than the Standard Metal Halide. However the opposite is actually true – the Standard MH has 40% more PAR than the HORTILUX BLUE yet the BLUE is clearly the better grow lamp due to the quality of the spectrum and how closely it mimics natural sunlight. How is this possible? The Standard MH produces 115,000 lumens while the HORTILUX BLUE MH produces 80,000 lumens. Since the brightness of the light directly affects a PAR measurement, the higher the Lumens are the higher the PAR measurement will be. In essence PAR is a measurement of intensity and is in no way related to the quality of the lights spectrum.