There is no need to be giving them ANY nutes at this point. When the tips of the leaves begin to curl under it almost always means that it is nute burn. There is really no need to be adding nutrients because even at low strength this begins to happen. Allow the plant to gain a larger root structure before you begin to add nutes. And when the time comes start VERY slowly and usually you will never want to use the recommended amount of nutrients that is on the bottle. Start at 15-20 percent and work your way up to 50% nute strength. Good luck, for now, flush with PH adjusted water. It may be a bit too late for those leaves and chances are they will not recover. Hope for new green growth and continue to flush until your babies look healthy again.
Happy growing, and good luck