So about 5 yrs ago,my wife and I moved to a new home. In the front yard by the steps was an in ground pre-fab pond filled with pea green algae from sitting in the full sun all the time. I had no idea anything was in it (pump and filter unplugged) until I spent a hot august saturday draining it. Well when I was finished I had a sparkling clean pond and about 3 or 4 six to eight inch goldfish! Well the next day after work, I walked over and found to my dismay,the pond was empty. The kid next door said a pelican came down and ate them. lol I think what he saw was a great blue heron. They are a crane like fishing bird here in Maryland. The next week I spent a small fortune on some gravel and wall stone,and built small stone wall up around the pond in my tree shaded backyard next to my lower deck complete with shade loving plants and ground cover. It really turned out nice if I say so myself. I will post pictures when I figure out how (old guy). I replaced the mucky old filter/pump box that sat in the bottom of the pool, with a TotalPond DD11560 560 GPH pond pump,fitted with a slip on foam pre-filter. This pumps up to a Fish Mate 500 G-UV filter box with an ultra violet light. I LOVE this filter by the way. It's a little overkill for a 160 gal pond, but it is so much easier to clean than that muddy bottom box. Well I've kept about 6-7 shubunkin and a carnival goldfish alive for about four years. I think they were freezing solid over the winters.Is that possible? Well a bird ate them last fall,and new fish I recently bought were sick and died within the this last month and I am learning to treat and test the water,and these issues are why I have searched for a sight like this where experts might guide this novice in the right direction. so Hello!