Ric's point is when you are talking about people it doesn't matter if you get hit by the back side of a shovel or the point of a knife ,they both will kill you but the knife will penetrate further.

Hillbilly's engineer point to me was clear -- while there are different facts to consider , like his on psi and Ponds on flat vs. mounded -- the point was not psi, but was use the right tool for the job , a sheepsfoot as Hillbilly stated.

Ponds keep us posted on the progress with your pond.