You may have seen these things advertised on TV. They're basically blown glass, forming a ball with a long neck, and they're intended to be filled with water and then put in the pot, with the neck pushed into the medium.
I can't see them working with coarser media, but they seem to work with my new Cymbidiums.
I received a couple for Christmas, and have used them exclusively to water my Cymbidiums.
Here are a couple observations that may prove useful.
1) the ease with which they penetrate the medium seems to reflect how recently the plants were repotted. The pink seems to have been repotted quite recently, while the yellow has probably not been repotted in a couple years. Something that is probably correlated with this is that the pink has half as many pseudobulbs, and seems to take up only half of the surface of the pot while the yellow looks like it is crowded, with only a little of the surface of the medium even visible.2) probably due to the state of the medium in the respective pots, the pink seems to need more water (I need to refill the globe about 3 times as often) than the yellow. I would hazard a guess that it I gave the yellow as much water as the pink, I'd end up drowning its roots; I expect its medium is retaining more water and has less pore space, than the medium supporting the pink.
3) despite the apparent differences in the condition of their media, both seem to be very happy.As my experience with Cymbidiums and with aquaglobes is very short, I'll know better in a few months if these observations hold true.
Any thoughts, or anyone else with more experience with these things?
Cheers
Ted