Hi guys,
Does anyone know if acorus the green and white plant is a true aquatic plant?

well, I know that the sub-variety Japanese dwarf rush Acorus gramineus var. "pusillus" (as identified in old aquarium books) is a true aquatic flag/dwarf rush. The one you're referring to, a variegated form of the Grassy-leaved Sweet Flag (Acorus gramineus) is a bog plant. But may not adapt to submersion as well as its Japanese counterpart.