Welcome to the forum and good luck with your pond renovation. It sounds like you have been giving it some thought . Good idea to get an experienced pond builder/renovator. I suggest you contact Mike Otto and ask him a few questions. He is a forum member. See link/email below.

Link
http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=000103

Otto's info
Email Address: [email protected]
Location: texas
Occupation: lake construction
Homepage: http://www.ntin.net/~mikeotto