I voted for the air stone, but I dont know <_< . I LOVE the way the bubble walls look in tanks with ONLY gravel, but I had a really long bubble wall on the back wall of my tank(a tropical, with angel fish & such), and I had really tall plants in the back that reached the top of the water, and whenever I turned the wall on it would push the plants WAY over, like bend them, oh yeah, they were plastic so damage wasnt a problem, it just looked really weird & annoying, the angels LOVED it though

they would do the funniest thing! They would go to the top of the bubbles then swim DOWNWARD, AGAINST the flow of the bubbles!!!

Like they loved the challenge or something, it was TOO cute!!!!! (it was when they were itty bitty babies, their bodies(not including their angel fins) were only like the size of a nickle or a quarter, so sweet.
I just thought of it, I've never had "fancy" goldfish, I've only had the "cloe" kind from the carnival when I was a little girl. The fancy, with their long flowing tails, seem REALLY pretty, though.
~PetLover333