the white stuff could be "white fly". . j* b. C! b7 Y1 n8 oI 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.6 W$ \7 ~9 l% o1 `3 c6 A
Hibiscus is a typical plant, show helps a lot.