How often you water your phalaenopsis depends on their growing environment, specifically the temperature, humidity and light conditions. It is important to water phalaenopsis orchids when they starts to dry out, usually every four to seven days. Water them early in the morning to ensure complete evaporation by nightfall.
Plants in warm and dry conditions dry out faster than those in cooler conditions. Plants in plastic pots retain more water than those in clay pots. Therefore, it is important to water the phalaenopsis orchids according to their needs and not a fixed schedule.
To be sure, check for water residue in the pot. If there is none, it is time to water the phalaenopsis. The weight of the pot can also signal whether the phalaenopsis needs watering, as the pot is usually fairly light before watering and fairly heavy after watering.