Too much burning sunlight, like the afternoon sunlight can adversely affect your orchids
. You can see the symptoms by observing the leaves. If they turned yellowish, check the placement of your orchid. Yellow leaves can also indicate lack of nutrients. In order for your orchid to grow well, you have to provide them with suitable fertilizers. Read the packaging or ask the seller for advice. One of the reasons why some people fail in rowing beautiful orchids is because they don't fertilized the orchid properly. Beware that if you put too much fertilizer you can even kill the plant.