I brewed up a batch of fireside ale three days ago, but there was zero fermentation after 30 hours. The carboy was in a closet sitting at about 66 degrees. I added a small lamp (60w bulb), wrapped the carboy in a towel to minimize light exposure and it warmed it up to 71 degrees. The fermentation picked up and is moving along nicely now. What I'm wondering is will incandescent bulbs cause issues or is it only natural light?