We put in a small (don't snicker) 260 gallon above-ground pond (plastic kidney shaped) in 2005 (above ground because no one knows where the sprinkler system lines are). The first year, frogs flocked to our pond and sat on the slate sides sipping fruity cocktails with little umbrellas in their glasses. We had 18 on one occasion. Over the years our population has dwindled. A neighbor reported seeing a heron feeding at our pond on more than one occasion. I have seen a raccoon on our deck at night, so I think he's also helping himself to frogs. Meanwhile, a few years ago cattails began to appear in the pond. We didn't try to control them because we thought they would give the frogs more hiding spaces. The cattails have taken over about 2/3 of the pond. I am afraid to tear them out for fear they will create a hole in the plastic form. We don't see many frogs this year. Do we have too many cattails? We also have a water lily and some other weird weeds growing in it, and not too many problems--i.e., the water is relatively clear.