Ok, so we are doing up our backyard over the summer and I would love to have a fish pond out the back.
Our neighbors have a fish pond made of an old bath tub sunk into the ground and their fish do great. It does get very cold here but they keep the pump running and the water doesn't freeze over and haven't lost any fish.
What are some cheap things I could make a pond out of?
Would you be able to use concrete (cement)? We are concreting the backyard so could I just dig a hole and dump some in there or would that poison the fish?
Any ideas welcome :)

