Orchids should be watered every five to 10 days. This amount of water is sufficient for the roots of the orchid to stay healthy. Overwatering puts the roots at risk of drowning. If the climate outside is warm and humid, water every five days or so. If the climate is cooler, water closer to every 10 days. Your specific type of orchid might need to dry out completely between waterings. It is important to identify which orchid you have for further watering instructions.
Light is important to the orchid in mild doses. Direct sunlight all day long will damage the plant. Black blotches will appear on the leaves if if the plant is receiving too much light. In addition, too little light will prevent the plant from growing and photosynthesizing. For an ideal light situation, put your orchid in a window with a light curtain between it and the window. The curtain should let indirect light through to the orchid. A mini blind would work well in this situation. Windows facing south should also allow for just enough light to hit your orchid.
An orchid can usually stay in its pot for up to two years. If you notice the roots growing out over the side of the pot, then the plant needs to be repotted immediately before the roots die. When roots die, they take on a mushy texture. If there are dead roots, remove them while repotting the orchid. Once you have repotted the plant, wait about a week before resuming a normal watering pattern.