Using a mandolin slicer (or a knife) thinly slice the cucumber into even slices.

Stir the water, apple cider vinegar, dill, and salt together. Stir until combined.

Add the cucumber to a wide mouthed jar (liked this) and cover with vinegar mixture. You want the cucumber slices to be fully submerged, so rearrange the slices as needed.

Cover the jar and allow to chill in the fridge for at least an hour before serving. Store in the fridge for 4-5 more days.