It is important that you allow pine bark medium to dry sufficiently before rewatering. These wet and dry cycles help to control fungi and insect growth which leads to stronger root growth. You can tell when pine bark medium has dried sufficiently by either picking up the pot and feeling the weight (a dry pot will be very light compared to a wet pot); or by carefully digging down into the media – the media should be dry for the first 2 – 3cm (in small pots) and 4 – 5 cm in bigger pots.
How often you water the orchid will depend on the orchid type, pot type and time of year.