Do u have any way of refreshing the air in the root chambers? they need a fresh supply of oxygen, u could pick up some cheap air pumps and run lines into the root chamber, thats what i do. That might be the reason for the leaves curling down, as the roots will start to become useless when they rot. I would keep them in veg until u sort out the root issue. Adding h2o2 to the water will def. help out for the first week but u cant keep using it. I'm guessing the air is becoming far to stagnant. Once the plant picks up and the roots look better u could switch right into flowering, when there under stress, it's a pretty bad time to start flowering.