Corruption in Your Base
The best way to heal it is to make some Blessed Drops at Naia’s temple. If you put the drops onto the place where it’s corrupted, that’ll heal it right up.
You can also place Rootbeard Fungus over corruption stains to get rid of them but, if it’s near to your teleportation pad, you might not be able to place the fungus there.
So the Blessed Drops would be my recommendation!