We have a solar panel that pumps water into a big concrete tank that then fills the watering trough. Below this is a draw that collects water (when it rains) and catches the overflow to the trough. I have one ton of sodium bentonite and access to a D6 bulldozer. I plan to push up a dam in the draw at the downhill end and then put the bentonite on the bottom and sides. I would like to put a few catfish in it to make it interesting for the kids to fish but was wondering how deep i should make it and how big to make it hold 20-30 catfish or so. I dont want a huge pond and didnt know if anyone had the same thing