Yes, I have seen it before, many times. Not in real life but they're all over the internet. They work very well due to the built in aerator (filter?) and lights, things that many bowls won't have. They also come in very large sizes and as seen above, the conversion kits. I watched a video on YouTube once (also in disbelief about the practicality of these bowls) with a pair of clown fish in it. Appeared to work very well to my surprise.