Hello, my mother came to me for help with her tank but I have no idea what this suff is. She has a small tank with a betta that has a messed up swim bladder so he just floats at the top most the time. But recently we've been noticing a new fungus or something growing everywhere in his tank. It's a small white string with other strings branching off about half an inch up and it's on all the walls and plants after just two days. She changed the water and they immediately came back. Does anyone know what it is or how to get rid of it?