Usually you don't filter a typical pond... unless you are talking about a lined pond. If that is what you mean, you'll need to watch out, b/c the toes of those things will go right through the bottom of it. I'd go with a large sandfilter - size should match the amount of water you'll have.
Check with your home owners insurance as well. Often times having a 'dangerous' animal in an outdoor pond area means you have to have a fence over a certain height to keep kids out etc....
Check with your home owners insurance as well. Often times having a 'dangerous' animal in an outdoor pond area means you have to have a fence over a certain height to keep kids out etc....