The bubbles are caused by the air in your tank. The bubbles will go away when you get some water movement in the tank, or if you add a filter to the tank.
If you have a filter already then it is probably just not powerful enough to push all the air out of your aquarium. If the filter does not have any air pockets or holes for the air to escape from, then it will just float around in your aquarium and make bubbles!
The best way to get rid of this problem is to add an air stone with a strong current running through it. This will help push all that extra air out of your aquarium. Make sure that there are no holes on top of the stone (if you have one) in order for it to work properly!
Last modified: November 6, 2022