We have a whiskey barrel pond. Approx 25-30 gals. 3 shubunkins, I recently have learned that in order to keep 3 fish in there we need to filter the water well. So, we ordered a hang on back type filter, and when it arriveed , we were impressed with it, but it is NOT intended for outdoor use. (Our pond area is somewhat sheltered and we probably could shelter it more, but would rather find a filter intended for outdoor use.) The problem is that I have spent hours looking for small hang on back type filter and all I can find are the ones filtering 400 gph or more. That seems a bit much for our small pond.

anyone have any ideas on a small (perhaps less than 250 gallons) hang on back brand/model to use outdoors?

Well, actually, I have 400gph filters on all my 30 gallon tanks and the fish do splendidly. You should have at least ten times turnover an hour for goldies, so you are looking at about 300gph anyway.....

what about an internal filter - one that goes into the water? That could not be disturbed by the weather.....

I have a 300gph side hanging filter on the side of my half barrel, and it runs at full speed all the time. 400gph is probably fine, and you can slow the flow on many filters if it ends up more like a whirlpool spa.

Do you have any pics to share of your pond?