Where I used to live, our house had a backyard pond. When we sold the house, we decided to take the koi with us. Most were about 6" and I was able to keep them in my large cooler. I also had a large maybe 15" koi. While we were dis-mantling the pond, I kept him/her in my glass 100gallon tank until I was able to give them to my friend. One night, of course at 3am, I hear a loud crash and the sound of water spilling. It seems that somehow the koi cracked the glass and the whole panel shattered. Nothing worse than waking up at 3am and trying to catch a large flapping fish while avoiding glass shards and trying not to slip. I learned the hard way that's why large fish, like pacus etc... are called tankbusters. The koi survived and is now living at my friend's pond. The Doctor.