Eric,
one thought - you will be going a lot deeper than 6" with your pond, so why
not undercut the concrete before trying to break it up?
If you hit it now, a lot of the force will be absorbed by the ground.
If it is hanging in space, it is a lot more likely to fracture under its own
weight.
Remember not to be under it when it does :-)
HTH
Dave R
"Eric Hanson" wrote in message
m...
Hello,

I am planning on extending my pond in the coming weeks. The current
pond is about 22' x 7'. I want to dig an extension to make it an
L-shaped pond. The problem that I am having is that I would have to
"dig" through a 6" thick concrete walkway. And I have no idea how to
remove it safely and with a low cost. I quickly tried to pound it with
a sledgehammer, but it did little to the concrete. Not even a crack. I
quickly stopped because I was worried about the fish and vibrations.

Does anyone have any suggestions/comments?

Please see my site for images to get a better understanding of what I
am trying to do. I look forward to ANY responses. Thanks for your time

http://www.pobox.com/~ehanson/aquaria_pond.html

--
Eric Hanson