the white stuff could be "white fly".+ Y( A0 C! K- A R+ f! k6 y: w
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. 1 a/ o& L/ U% L* W: C8 AHibiscus is a typical plant, show helps a lot.