
Which orchids can be grown?
Most popular orchids will more or less thrive in hydroponic culture: Paphiopedilums, Phragmipediums, Masdevallias, Phalaenopsis, Cattleyas, Cymbidiums, Oncidiums, Dendrobiums, Epidendrums, Miltoniopsis, Pleurothallids and Zygopetalums.
Exceptions would be very big or "thirsty" plants or those whose roots must dry sometimes completely and even those that require dry rest like Dendrobium nobile.
Advantages of Passive Hydroponics
Its simplicity and effectiveness. No guessing about watering and fertilizing, no media decomposition, practically no root rot, healthy plants, fine blooming, no moving parts, low cost, reusable media. In hot and dry environments, passive hydroponics may help, since the roots stay in a high humidity chamber with some air flow.
Disadvantages
The main disadvantage can sometimes be the need of more frequent watering, especially when plants begin to fill their pots, are big or otherwise demand lots of water. Obviously, a bigger water pot/reservoir may help (or side holes higher up on the pot). If the sides of the translucent containers receive enough light exposure then algae will grow on the outer layer of the potting media. This is mainly an aesthetic concern and not a big problem indoors. If the medium consists of small expanded clay pebbles and the plant is newly established then tipping it over may cause the spilling of said medium and plant. Build up of salts (fertilizer) which are not easily removed from clay substrates and "reservoir" (lower section below drainage holes). If chemicals are used for pest and/or disease control excess is retained.










