Water Gardening: Half barrel pond vs aquarium, 1 by Sundownr

Sundownr wrote:
I have a plastic half barrel pond (see photo), initially created for the azolla (Carolina Mosquito Fern) floating water plant's fertilizer properties, and collect rain water, to help water next year's berry beds. The azolla hasn't spread over the surface as much as I thought it would, and now I'm accidently breeding mosquitoes!! I want to add feeder goldfish to eat the skeeters, but have been told I need a pump & filter to clean and oxygenate the water, and the fish won't live in the barrel during the winter months.

My question is, can I use a pump and filter system from a 25 gallon home aquarium, if I can shelter the pump from the elements (barrel pond holds ~ 27-1/2 gallons)? An added bonus would be to over-winter the fish and plants in the aquarium, too.

I have no experience with ponds, but have had many aquariums over the years.

I appreciate any help or ideas!
Thanks,
Bev