To Rock or not to Rock?

[bagsmom]

I see you have a little screen shot of The Pond Digger. I built my pond totally according to his fish pond tutorial. I have larger pond pebbles on the bottom and shelves -- not small pea gravel. Only a thin layer - probably one rock thick. When I built up the walls with larger stones, I did squirt a small amount of waterfall foam between the rocks. It helped hold them together and also filled up a lot of voids. I'm sure there is some gunk getting behind there, but there doesn't seem to be much. So far so good. I like my rocks!