There is absolutely no truth to that statement. Yes MH is the preferable spectrum but they will still veg fine with a HPS, you will not get any stretching as long as you don't move the too ar away.
I didn't say they wouldn't veg fine. I was just stating what I've learned from experience. My hps vegged plants were kinda stretchy, as my MH plants weren't. If there is no truth to my statement, are you saying the grower wouldn't be happier with a MH for veg? [FONT=verdana, helvetica, geneva]
[FONT=Verdana, Arial, Helvetica, sans-serif]Q What is the difference between MH and HPS?[/FONT][/FONT] [FONT=verdana, helvetica, geneva]
[FONT=Verdana, Arial, Helvetica, sans-serif]A Metal Halide HID lamps have a balanced light spectrum which offers the most natural light output. Metal Halide's balanced spectrum contains the common blue and red wavelengths needed by plants for the most rapid growth. Plants can be grown from start to finish using metal halide lighting systems. Metal Halide lighting promotes leaf growth.
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[FONT=Verdana, Arial, Helvetica, sans-serif]High Pressure Sodium lamps are more efficient than Metal Halide, producing the highest number of lumens per watt - about 10-15% more than a Metal Halide bulb. HPS emits an orange/yellow color that is similar to the sun's spectrum in the mid day. This type of light promotes flower growth. However, the lack of blue spectrum light can sometimes make a plant stretch during the vegetative growth stage. HPS should be used as a supplemental light in your greenhouse or sunroom.
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