Having a very old pond with heavy muck build-up, I was most curious after setting them in May, 2012 how deep in the muck they might be when I went out to clean them as I set them directly on the pond bottom.
This is a picture of a Vertex air station of which I have 4 (3 shallow, 1 deep):
The very, very soft muck near and around the air station was at least a foot thick but the air station had not sunk into it, with the disks still well above the muck (as well as the platform). And that's after 3+ years of being undisturbed.
So as I too was curious if I was stirring things up, I am happy to report they are where I personally would like them to be due to the make-up of my pond. Low enough to circulate as much water as possible, but not too low as to be pulling up the muck.
Keith
PS - As a disclaimer, I have no idea what the surroundings of the air station actually "looked" like, for instance if I was able to view the contour of the pond bottom where the air station is from a distance. But that would be interesting!
