These bulbs are optimal for your flowering stage. These bulbs also have on average 5000 more lumens than a standard HPS bulb and with over 90% red and just a little blue make these a cut above their standard counterpart. Plants still need a little of the blue spectrum even during the final stages for proper plant health. The Hortilux bulbs address this without sacrificing any of it's blooming benefits. All bulbs come with a one year warranty.