Hi, looking for advice recently set up a new tank for my betta he was getting bullied in my large tank, after cleaning it out yesterday & adding new plants I,ve noticed air bubbles covering the whole of my water line these start to disappear when I lift the lid? The filter I have has a spray bar which hangs out the water is it this? Do I need to worry? The tank is 25litre, no sign of any paras at the moment seeded the tank with ornaments etc from my matured tank. Any advice would be great.