My pothos is sitting in my kitchen in the corner between two windows. It gets the eastern sun until about noon. My blinds are constantly drawn and I noticed that the edges of the plant is black on the leaves. Is it getting too much sun?
Check the soil to make sure the first inch or so is drying out before watering.
Over watering can cause root rot.
Also if watering with conditioned water it can cause black edges on the plant. Try leaving the water to sit 24 hours before using for plant watering.
If the dark edges spread it could be a fungus. Neem Oil is a good treatment.
Here is a link to refresh you on the care requirements.