LIGHT
Moth orchids like bright indirect light. They will thrive in eastern, or shady western or southern exposures. You may also be able to get some blooms in a bright northern window. Do not place phalaenopsis in full sun.  Let the foliage be your guide: leaves should be medium green, and firm. Floppy long dark green leaves means that the phal is not getting enough light.

 Excessive dark reddish pigmentation on the leaves may indicate excessive light which can result in fewer and smaller flowers. Phals can also be grown very well under lights, especially fluorescent tubes.

In general, aim for foliage that is a light green in color. If your plant blooms well then that means it is probably getting optimal light.

Medium green firm leaves indicates this phalaenopsis is getting enough light. The very slight reddish tinge near the base indicates that no more light is necessary.

 Light is of course cloesly related to temperature>