I read from a lot of people that flooding during lights off isn't neccessary. I wasn't flooding during lights off for the last 3 weeks, and I don't like the look of my plants, so I changed it. I read several grows where people flood every 4 hours, 24 hours a day, and had good results. I remember when I first started growing in soil....If I had listened to every "general consensus" for soil growing, I would not have had the great crops I have had.