What an interesting topic so thought I'd comment....I am a High School Visual Arts Teacher at Saunders Secondary School in London. My tank is what I consider my canvass so I have fun planning and playing with all the colours and textures that make up a work of art but in this case a living one. I know of other teachers who have tanks and Beal Secondary School actually has one between the science offices. You can keep it as simple or a complex as you want and still get the same amount of joy and pleasure. It is a great way to relax after school !