If you notice a dusting of mold in your soil/can don't fret! There is actually a very easy way to rectify this. Mix some cinnamon into warm water and let it steep overnight. Strain the mixture and fill it in a spray bottle. Spray your soil with this solution. Cinnamon is a natural antifungal and it should do the trick.
We here at Back to the Roots really believe in sustainability which is the main reason we ask you to keep your original cans.