the white stuff could be "white fly".( n. ?6 V/ ~6 G: Z$ H! V; @% U1 R
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. ) V2 }: x, a, Y8 ?$ d0 M) l$ p- o$ \Hibiscus is a typical plant, show helps a lot.