Here's a pic of our new pond. We made LOADS of mistakes making this...... so if you're crazy enough to do this, feel free to reach out to me so you can learn from our mistakes. It is awesome now that it's done and all the fish are safe.
The pond is 10'x14'x5'. We first tried with cinder block filled with concrete and rebar. When we filled it you could see the wall bow out. Leaked everywhere .... so we took that down and then dug down 2 feet and have 3 feet above ground. We used poured concrete with 8" thick walls. We coated the walls with pond sealant, so the concrete would mess up the Ph. We have a GC Tek pond filter that is rated for 17000 gallons. With the thought that there's never TOO Much filtration. We also have a second pump and a large air pump to move LOTS of water. I like a lot of flow in the tank. We did put in a 4 ft. window in the side so you can get that "Tank view" . LOTS of work.... but worth it...... although my wife might kill me in my sleep.