I have homemade reflectors. They are shiny, metal sheets lining the sides, the front, the back and the top of the inside of my homemade hood. My fertilization is pretty good, around 5ppm of nitrate, 1 ppm of phosphate. I also add potassium, a little bit of iron and Flourish for micronutrients. Still, the glossos are beginning to grow upward and they are spreading at a very slow speed.