Walmart has cheapy cheap aquarium heaters that are preset at 20 degrees that sre fully submersible. 15$ or somethingCan you use aquarium heaters outside? We have a patio pond with 3 goldfish and I've been looking for something to keep it from freezing over when it gets really cold. We used to bring the fish inside in the winter but they have gotten so big.
Would be nice to find something I could just get 2 of to keep the ducks and the fish thawed this winter![]()