Aglaonema does not like cold water. Water it sparingly, with room-temperature water, just enough to moisten the soil. Avoid overwatering, and allow the soil to dry out slightly between waterings. If placed in a sunnier location, it will require more frequent watering. Out of the sun, on the other hand, it needs lower temperatures, less water and less humidity. Aglaonema is a slow-growing plant and should not be over-fed. Use indoor plant food or an all-purpose fertilizer like 20-20-20 every three months from March to October.