How to Water your Moth Orchids
Moth orchids are epiphytic--they grow on other trees, with roots clinging to the bark and exposed. Most hobbyists grow phalaenopsis in pots since its far more convenient. Moth orchids receive frequent rainfall during their growing season--the roots are wet thoroughly, but dry out a bit, before they are wet again.

In pots, orchids roots are exposed to less air and do not dry as quickly. If you overwater them, the roots end up rotting and the plant will not survive. 

Moth orchids also need to be kept moist since they have no pseudobulbs to store water unlike many other types of orchids.  Allow them to dry out very slightly before watering again. Never let phals get bone-dry.  As with all orchids, water plants thoroughly early in the day, so that the leaves are dry by nightfall. It is especially important not to let water sit in the crown of the plant (where the leaves emerge) as phalaenopsis are susceptible to crown rot.  Filtered tap water, or rain water, is best. Water should be tepid, not cold, i.e. above 60 degrees. Flush the growing mix thoroughly and copiously with a gentle stream, or spray, of water and then allow the pot to drain. Most of the excess will drain out from the bottom of the pot. This is important to i) make sure all the roots are wet, and to flush out excess salts from the growing mix.

Your watering schedules will vary considerably depending on light and temperature conditions. Plants may dry out rapidly in warm dry conditions, needing water every few days, or may remain moist in cooler seasons for longer periods of time. Water your moth orchid according to its need, not your schedule.   

Plastic pots retain more water than clay pots. Larger pots dry out more slowly than smaller ones. And some orchid potting mixes retain more water than others. Keep this in mind as well--moth orchid plants in different size pots and/or  mixes will not all need watering on the same schedule.

Next, you will learn how to water your phalaenopsis orchid.