the white stuff could be "white fly". . e, Q# ^: ]& q4 v* X" |& e4 qI 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.2 s* ~/ s7 z6 I9 e- l& B) X* i
Hibiscus is a typical plant, show helps a lot.