the white stuff could be "white fly". ' T5 h, t/ U' D6 M1 V( _9 C+ ]I had the same problem before. It because your plant is too wet. I showed the leaves twice a day for a whole week, then the white filies were all gone.5 @& e: d; Z" x/ v7 K: l
Hibiscus is a typical plant, show helps a lot.