You can place your orchid in any container with enough room for roots to grow, but it is fun to use glass so you can observe the progress of the plant. The container doesn’t need to be very deep but high curved sides can help support the plant and keep it from flopping over. Many hydroponic orchid growers also use clay pebbles in the bottom to help support roots and rise the crown from the moisture to prevent rot. The medium might seem to be straightforward – water – but there are good and bad types. Some municipalities treat their water until it is laden with chemicals and can be quite toxic to plants. A better route is using rainwater, or distilled. It is important to use tepid water to avoid shocking the plant.
Some growers simply leave their orchid in the water all the time with weekly or biweekly water changes. Others swear by soaking the orchid for 2 days and then allowing it to dry for 5 days.
one could set up most orchids to grow in water as long as there was oxygen exchanged. For instance, if the water was re-circulated or had a splash fountain or a bubbler we believe we could grow totally in water– as long as we keep the plant above the water and the roots in the water.