Never have I seen this. I've grown in several public/private/retail greenhouses and all were simply watered with a hose.

Not to say there aren't crazy ways to do it but the standard is hose watering.

You can grow epiphytic orchids in just water. As an experiment I placed a couple in bottles of water and observed them for about 3 month. All of the roots died off and a new root system promptly formed. The plants were thriving. Semihydroponic growing works very well with the roots sitting in 1" or a little less of water. This guy is simply doing a semihydroponic system using 3" of water instead of the usual 3/4".

I see no reason why it should not work. The roots will adapt to whatever is needed.

Nick

I'll keep checking on those orchids. Interesting to hear that it could work.

This is a flood irrigation method sometimes used for watering greenhouse flower crops (usually annuals). Water, sometimes fertilizer is piped in as well, fills the growing table up to about two inches and the potting soil absorbs the water. Each section is typically wet, or full, for about 10-15 minutes. It should not be recommended for orchids even if it is used temporarily.