I've been using semi-hydro materials and techniques for just a few weeks now. So far my paphiopedilum seedlings and phalaenopsis transplanted into semi-hydro pots with PrimeAgra are doing very well--in fact, better than I expected.
What I find I have to fight with the semi-hydro technique and materials is the psychological effect of two things: 1) the inevitable association of the word "hydro" (as in hydroponics) with water, and 2) the fact that the PrimeAgra leca (lightweight expanded clay aggregate) has a tendency to look dry very quickly or soon at its top surface. Both of these things make me tend to be a little too inclined to add water.
What I have to keep reminding myself of is that semi-hydroponics does
not mean aquatic. Orchids are not aquatic plants.
Just because semi-hydro pots and techniques include a liquid reservoir at the bottom does not mean that the plants should be grown in water, nor in wetter conditions than they would normally encounter in other media or in nature.
I'm finding therefore that the greatest challenge for me so far with semi-hydro is to re-train myself and restrain myself from overwatering. Even though the reservoir and the PrimeAgra
can hold a lot of water, I find myself constantly judging and adjusting the moisture content of the medium based on my 8 years or so with traditional orchid potting media and I try to make the PrimeAgra just moist most of the time, not wet.
Just my own two-cents worth addition to the discussion.
