I got terraria for Christmas and have been having lots of fun playing. Recently i have entered hard mode and i need help in stopping biome spreading. Before hard mode i made a 6 block wide tunnel around all of my corruption biomes but somehow it has managed to spread into my ice biome. Should I ditch my world? I really want to make my first play through a long and good one and don't want my whole world to become corrupted but it already seems out of control if it spread to my ice biome.