Always water early in the day so that your orchids dry out by nighttime. The proper frequency of watering will depend on the climatic conditions where you live. In general, water once a week during the winter and twice a week when the weather turns warm and dry. The size of your orchid container also helps determine how often you need to water, regardless of climate conditions. Typically, a 6-inch pot needs water every 7 days and a 4-inch pot needs water every 5 to 6 days. 

The structure of the leaves corresponds to the specific habitat of the plant. Species that typically bask in sunlight, or grow on sites which can be occasionally very dry, have thick, leathery leaves and the laminae are covered by a waxy cuticle to retain their necessary water supply. Shade-loving species, on the other hand, have long, thin leaves.
Here again, the type of potting mixture will be a major factor in determining how often you should water your orchid. You should also pay attention to the condition of the potting mixture, as aged growing medium that has broken down into finer particles will hold more water and take longer to drain than fresh medium, thus requiring less frequent watering.
ust about anything, it sounds simple until you get down to actually doing it, and then the questions come up. But once you get the hang of it, you’ll realize how easy it is. Here are some specifics for successful ice cube watering.One thing you may find yourself wondering is “what size should the ice cubes be?” since there seems to be no standard size or shape anymore. It should melt down to about a ¼ cup of water. As long as that’s the case, the size of the cube is only an issue if it’s crushed ice. The point of using ice cubes is that they melt slowly – releasing the water in a slow drip. So you don’t want to use anything that will melt quickly.
The Sobralia orchid genus grows ubiquitously in much of South and Central America; I've heard them called "ditchweed"! They have beautiful, short-lived flowers whose appearance is somewhat similar to a large Cattleya orchid. Flowers can be more than 6 inches (15cm) across in some species. The plants can get quite large, however, so you need to have enough space for them!
Cymbidium carry tall stems with many flowers that have a more typical orchid shape. They are easily identified by their grassy leaves, and they readily form large clumps. Most common are the cool-flowering types, which need to experience a cooler winter (nights in the 40s for some time in the fall) in order to initiate flowering. Once the flowers open, they can last for up to two months or more, especially in a cool environment. These are very showy and rewarding plants, and a plant in a six-inch pot can carry three stems with 15 or more flowers each, depending on the type.