Firstly place your plant away from cold draughts, in indirect light and not above a radiator. Also, keep away from bananas! (Bananas release ethylene gas when ripening which makes the flowers wilt).
Phalaenopsis can tolerate low light; a north or east-facing window would be fine. For Phalaenopsis orchids, it is very simple to determine their watering needs. These orchids are grown in clear pots so you will be able to see how wet the roots are.
Green roots are sufficiently damp and as they turn silvery-white, the plant will require watering. Use tepid water and allow the water to drain completely and then place back into its decorative pot. Every other time you water the plant, add some orchid food.
Once the flowers on your orchid have faded there are two options; you can either cut the flower spike back to 3mm above the next node down. This will encourage the development of a new flower spike from the node; however, the flowers may be smaller. The second option is to remove the flower spike completely, cutting it a few centimetres from the base of the flower spike. It will take longer to produce more flowers but the new flower spike will be a nicer shape. Don’t forget to stake when the spike is approximately 30cm tall.
If your orchid hasn’t re-bloomed it may not be getting enough light so you should move it to a brighter position. Often, if you provide a greater difference between daytime and nighttime temperatures this can trigger a new flower spike to develop. Orchids like to be fairly tight in their pots. However, if your orchid is climbing out of its pot or if the bark has broken down it is time to re-pot your orchid. An ideal time to do this would be when the orchid has finished flowering and when the roots are actively growing (growing roots have a green tip).
Re-potting is done by removing the orchid from its pot and carefully removing the old bark from the roots. Sterile secateurs or scissors should be used to remove old or damaged roots (healthy roots are firm and white or green) and healthy roots can be shortened to a minimum of 10cm. The plant can be re-potted into the same pot or a slightly larger one if necessary, using specialist orchid bark. Hold the plant in a central position at the correct level and fill the pot with bark, firmly but carefully pressing bark around the roots to anchor the plant in the pot. Spray the surface of the compost with water regularly to encourage the growth of new roots but do not water until a week after re-potting to avoid fungal problems