Today when I came home (I was away for some days), I saw for the very first time my 9000 liter above ground pond (with window-glases) with nearly cristal clear water. You can see from one of the windows easily 4m to the opposite wall. And wow, I had supposed it would look great, but looks now really amazing. One of the main reasons for this is because I made a lot of underwater reliefs with big granite rocks and sand. You could surely "update" your great monster-fish-pond when you would add sand and stones too.