Watering is essential for your calathea exotica every 1-2 weeks (depending on environment) till the soil dries between waterings.
Calathea exotica thrives in indirect light that ranges from low to medium. It is tolerant of modest indirect light.
Generally, your calathea exotica prefers 50°F temperature, but it can also tolerate a range of 55°F to 85°F.
If possible, calathea exotica grows better under increased humidity. Morning dew or a humidifier in the room will help your plant.