the white stuff could be "white fly".2 [" Y- a+ v. y! ^
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.0 f& s5 L! }0 W* L1 e+ \2 A- b9 T
Hibiscus is a typical plant, show helps a lot.