it is possible that it might be gas because from what ive learned they go up to the top & gulp air when they are hungry. and is he floating bum first or just floating all together, some axies to float just because they want to, but if floating is stressing him out all i can offer is to lower the water or put him in a container with dechlorinated water just covering him but so he can touch the ground & wait for someone more experianced to reply :happy: good luck!