Having counted the cement bricks and if they are standard 16 inch contractors bricks, the pond could be 62 square feet, but because of the bucket and tub it doesn't look like its 3 feet deep. ( Meaning it could hold anywhere from 500 gallons to 1400) Petsmart and Walmart have goldfish labeled "feeder goldfish" usually for ten cents each and there are usually a couple of dead ones in the tank and they are pretty small - like about 1 inch. It wouldn't be unusual for a couple to die after you get them home. The other "goldfish" are bigger and probably at least 25 cents or more. I have always assumed that is what the difference is and that the feeder goldfish people buy to feed to other critters. I can't imagine that N. Carolina doesn't have herons or snakes. Our neighbors had both herons and an eagle clean out their trout ponds - and they were big eatable size trout! I had a bear in my little tiny pond a couple of years ago, but he just wanted a drink. Fortunately the dogs were in the house so there was no contact and we now have a fence.