Thank you all very much for your help and advice. I was amazed how contradictory some can be as to which species can live together. My son is having his bedroom remodelled in a basically steampunk theme (with skylanders and minecraft worked in, my job apparently) so I'm going to ask my Dad to build a stand out of square piping (makes for nice strong welds) and extend the legs across the base of his cabinets, giving the tank extra strong support and the furniture and floor will have a more even weight distribution! Plus, it'll add to the steampunk look. Thank you so much for your help, from me and the person below. (Forgive the dingy, grainy picture, it's 3am and all I have is a small camera and an led bedside light.)
Oh, he's also taken to posing for the camera, look front, left, right, front… He seemed most put out when I stopped!
Read more: Goldfish related for anybody who helped me to help Scorch, especially Eduardo and Noselessman?