Building this fish pond is also very simple, using only some tiles, glass glue and plastic paper. As long as the key problem of waterproofing is solved, the rest are minor problems.
The roof was originally waterproof, so we added a waterproof layer when we built it, and we were careful not to destroy the original structure, so that we could safely raise fish.
The temperature here is not high at present. Let's put some aquatic plants in the fish pond first, and then make a sunshade when the temperature rises. If there are many fish, add a solar oxygen machine. In this comfortable environment, fish will naturally have no problems.