Quote Originally Posted by arielgasca420 View Post
clay also has a high salt content which is why you cannot use it for carnivorous plants. it also shrinks and swells with temperature differences. however it has small colloids so I am uncertain if it will cause impaction
It would depend on the type of clay and a lot of clay found here becomes near solid even when wet. Not only this, but it also doesn't absorb water well once it settles. Water will pool atop the clay.