My particular question was concerning the type of concrete. I don't want
to poison the fishes, and I don't want to use a liner, so the components
of the concrete are very important. Gunite and/or shotcrete may be
suitable, but I'd like to hear that from someone who actually has a
concrete pond like that with fishies.



New concrete turns the water alkaline. Let it age before use. Or roll on a
coat of asphalt emulsion.