Sunlight vs. T5s

[daddydoall]

Even with a GH, depending on your latitude and natural shading, artificial light can be helpful supplement in shorter day seasons. I use a 400W vapor lamp on a timer up to 3 hr before sun rise (on the GH, not the horizon), and up to 3hr after sundown to provide 12hrs. In addition to light, it helps to keep the GH warm. My electric is solar, so no guilt here.