Yes, thats another thing, I don't know if this is possible at all for you but we have our sump pump pipe running into our pond (since only fresh cold groundwater goes through our sump pump). This way when the sump pump puts about 5 gallons of water into the pond every hour it keeps the pond topped off, then we built a little run-off area and a creek for the run-off to flow into (to prevent the pond from ever overflowing). Have been doing this for a few years and its worked like a charm, never had any problems.
Here are some pictures Reefgirl:
Here is the giant lily-pad I was talking about, with frying pan-sized leaves.
Hard to see to the bottom of the pond from a photo, but the water is crystal-clear.
