the white stuff could be "white fly".$ G+ T6 ~ T$ F" B3 M& `
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. 9 o) z8 q1 \ c5 t4 W! R5 \( ?Hibiscus is a typical plant, show helps a lot.