the white stuff could be "white fly". ! W& `' W( S5 z2 K2 uI 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.; V! P" L6 \8 G0 a2 m- {0 V0 B+ m
Hibiscus is a typical plant, show helps a lot.