In a large bowl add the lemon juice and cold water, gently stir. Clean the apples and remove the stem. Using a Mandoline or sharp knife, slice the apples about 1/4-1/3″ thick. Place the sliced apples into the lemon water. Gently stir to ensure that all of the slices are coated with the lemon water. Soak for a 30 seconds to a minute.
Drain the apples completely. If making cinnamon apples, place the drained apples back in the bowl, add in the cinnamon oil and ground cinnamon. Gently mix to combine.
On each rack add a single layer of apples. Once all of the apple slices have been placed, close the doors of the unit and turn it on.
Set the time to 7 hours (if the slices are very thin) or 10 hours (if they are thicker) and the temp to 135F. Press start and let it go.
Once done, test a chip. If it is crispy and crunchy then your apple chips are done. If not, continue cooking. To store, place in an air tight container.