Goldfish are not as bad as koi or carp for rooting in the sediments. Goldfish can cause water clarity problems when there are too many and they start searching the sediments for food items, thus my suggestion to keep their numbers low. Eight to 12 goldfish would be plenty in your size of pond. You shouldn't have fish to human parasite issues with the fish. One small largemouth bass 4"-5"-7" long should help you keep the numbers of goldfish low. Inplace of your current fish you could add 4-8 male bluegill. No reproduction and they would keep insects/bugs to a minimum. To learn more about selecting only male BG do homework and study the info in the informative link below an PM me if you need more help. Remember only keep those BG that definately have the largest ear tabs indicating male gender. Dark spots on the forehead are also characteristic of males.
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=21481

Does the pond have a drain?? Sediments from decayed plants internal and wind blown will gradually accumulate about 1"+/- per year in the pond and contribute to water stain and possibly cloudy water? Sediments should be periodically removed in a pond for your long term goals.

Last edited by Bill Cody; 04/05/12 09:38 AM.

aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management