Light: Peperomia metallica will do best with bright, indirect light. They can be kept in medium indirect light but be mindful of watering. The lower the light the less frequently your plant will need to be watered.
Water: Allow your Peperomia metallica to go about halfway dry between watering. Peperomia have shallow roots that can quickly rot if allowed to stay too moist. If you're having a hard time knowing when to water your Peperomia metallica pay attention to your plant, you'll notice the leaves will go slightly limp when it's time to water.