Hydroponic vs. Semi-Hydroponic?

[datousteve]

Is there a difference or are both of these the same thing?

For example, the hydroponic kit below appears to be applying the same concepts as the S/H kits I've seen elsewhere. Am I missing something?

Kelley's Korner Orchid Supplies

[Ray]

They are both hydroponics.

"Semi-Hydroponics" is a term I made up to differentiate the single-pot, passive culture technique from the more traditional methods of ebb-and-flow, thin film nutrient technique, aeroponics, etc., which all require a much greater investment in equipment and monitoring devices. Those systems are actually poorly applicable to orchid growing, as they share a nutrient bath among the plants, which is an ideal pathway for sharing plant pathogens, as well.

The three-component pots Jan and Ulla sell can certainly be considered a way to implement S/H culture (they are often referred-to as "Luwassa pots"). I have some plants in my office in them. There are some pro's and con's of their use versus the single-component pots I created.

• Luwassa pots are far better looking than converted deli containers (and the wide array of other containers folks use to make pots).
• Being opaque, algae buildup, while primarily only an aesthetic issue anyway, is less of a concern.
• Luwassa pots, however, are far more expensive. ($3 vs $0.50 for a 3" pot, $5.45 vs $0.75 for 4", etc.)
• Being opaque, it is not as easy to see how the root systems are doing.
• The upper limit on the reservoir is the top of the pot, so one can overfill them and drown your plants. That is impossible in a pot of my design.
• Watering is easier in my pots: fill to the top and let it drain, which flushes the medium and refreshes the reservoir. Adding solution to a Luwassa pot merely "tops up" the reservoir, so you really don't know what the chemistry of it is, and you must remove the plant and culture pot from the outer pot periodically to manually flush the medium.

As I said, I use both, but if I want a more decorative semi-hydroponic pot for displaying a tropical plant, for example, I convert a traditional plastic pot and tray from K-Mart of the like, by drilling two quarter-inch holes in the sidewall, sealing the drainage holes in the bottom, and gluing it to the tray. It looks nice, and the tray becomes a secondary containment of overflow when watering. (I usually dump that afterward)

[goodgollymissmolly]

I agree with Ray. I do both, but not hydroponics for orchids.

I think it's fair to say that hydroponics, whether Flood and Drain ( Ray's ebb and flow) or spray technique is an automated, capital demanding process system.

Semi Hydro as Ray has dubbed it is a simple, manual method for growing orchids which requires little expense or understanding of control systems.

Those are my definitions, but I guess everyone could make their own and still be right.