You will want to put a liner under the rocks and have it come up high enough
on the sides to contain any water. The silicone or foam will get the water
to run over the tops of the rocks, so it is more noticeable, but some will
leak behind the rocks, and you want to have it run into the pond, rather
than the ground around the pond.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html


"mark" wrote in message
a...
hi can I use silicon to fill in the cracks in my waterfall,I want to use
silicon so the water will not run down the cracks but flow over
them,should
I still use a liner. I'm a newbee to the waterfall so any advice on water
flow is appreciated.