On the small aquarium. The betta was swimming above the round bubble wand, playing in the bubbles. He does that fairly often. It's fun to watch. When I had the one with the LED lights that changed colours, the last one would hide under it to avoid the light. I think it hurt his eyes, even though that's what came with the tank. Then I took it out and put a white light that clips above the tank in, and a normal bubble stone. This one has only known this setup. He only sits under the stone when resting. Otherwise he's swimming around the three-gallon tank or playing with the bubbles. I think he enjoys it, and it's much better than those little cups or vases they normally put those fish in.