That site is just like hundreds of other sites that only exist to send traffic to Amazon. They are bullshit.
It's Amare Time! Jk. The best light on Amazon is by far the UpDayDay CMH/LED for great veg & flower + the HPS/LED if you want hps buds. How's it going? Sent from my SM-N981U using Grasscity Forum mobile app
Simple earth science, spring the position of the sun is farther away but moving closer, the spectrum is blue, thus outdoor growing is in full swing, to achieve that spectrum, a metal halide is used. USA, June 21 is our longest day, after that, the sun is moving further away, and day light now starts to decrease about 3 minutes per day. As the sun moves further away and day light hour decrease to about 12 hrs of daylight, bingo, flowering begins and the sun's spectrum is now orange and yellow, which is a hps, high pressure sodium. Indoor growers simply try to mimic mother nature. Indoors, I cranked ac down to 68 degrees to simulate fall, seemed to kick start bud phase hard.