I have an Aerangis fastuosa in semi hydroponics. Essentially smashed clay as the medium instead of leica. Also, the plant's pot is sitting in a uncovered glass vase to keep up the humidity which is typically around ~80%.
Recently I noticed hundreds of small black insects moving about in the medium. They are about 0.1 mm long or less (very small), very fast moving (always moving), and black in coloration. They tend to reside in the wet area of the clay. I have a microscope, so I took a video of one of them that I knocked off onto a piece of white paper. Video in the YouTube link below.
pest - YouTube
Can somebody ID this insect for me? Is this insect damaging to the plant? And most importantly how do I get rid of it? What insecticides should I buy?