I do not candle anymore after the initial time I see good veins. My concern is that when you candle, especially close to the hatch date, the snakes move in the eggs probably trying to escape the light. I imagine it is very bright in contrast to their warm, dark little world they've been residing in for the last 50+ days. When they do squirm you run the risk of them twisting their umbilicus and that is a serious complication. While I have no proof of this, it really isn't much of a stretch to deduce.