Recently bought a new house and the wife wanted a pond. Well turns out homeowners association doesn't allow ponds so I said screw it we will make one inside lol. I want the pond to be fairly big which makes me want to stray from plywood but at the same time I'm not sure if I want to do cinder block main reason is the concrete part if we ever decide to sell the house. I guess I'm just trying to find some pros and cons to each. Haven't decided what I will put in it I already have a big tank with arowana, shovel nose cat and a clown knife maybe convert them over and get a few other species. Was wanting to do at least 800 gallons.