Is it ok to put some red rose minnons in my 144gal pond with goldfish?If yes,will it live over winter. I live in southern Ontario.

Have the goldfish overwintered in there successfully before? If so, the rosy reds should do okay as well. You want to be sure that the goldfish and/or rosy reds don't reproduce so much that the pond is overcrowded. The rosy reds and goldfish should get along but will eat each other's eggs and fry if they can find some. Rosy reds are just as hardy as goldfish if not more.