we've had this goldfish for quite some time now and we bought him a bigger tank a couple of months ago. it came with a bubble-making filter thing that worked for the first few weeks then stopped working, so we just took it out since he never had one before anyway. a few days ago he was lying on the bottom of his tank and we figured he was gonna die, but we weren't ready to give up that easily so we went to the pet store and asked the guy there, he said that the fish probably needed his water changed because we hadn't changed it yet (usually we would change it when it started looking grimy but it still looked ok), he said sometimes even clean looking water can be full of waste and it could have made him sick. we didn't do a full water change, we got this siphon that lets you change part of it at a time and it also sucks the gravel up and cleans it out so that you don't have to fully change it. we also got a new bubble thing for his tank because it's supposed to keep the water flowing and get bad gasses upto the surface or something. so it's been 3 days and we've done this once a day now and he's moving around a little more now, but when he gets off the ground he swims for a second upside down or sideways then goes to the top of the tank and flips himself right side up before swimming down to the bottom again, or sometimes he looks like he's standing on his head for a few seconds then he swims around to find a place to rest again, like he's lost his sense of direction. when i pour the new water in when i was changing it he would actually start to swim around normally to try and get away from the water as it was pouring in. he just started doing this today, before he was more or less just laying on the ground and moving only slightly. is the fact that he's moving more a good thing or is it bad that he's moving in such a weird way? being that he's a goldfish i don't expect too much but i would be real happy if he could pull through so i['m hoping these are good signs rather than bad, i just don't want to get my hopes up.