What happens if your filter is too strong? Can It harm your Betta Fish? ;.; && bubble nests just means they are healthy enough to breed? And I don`t think Blue is lazy cause he swims around a lot xDBubble nests can look like anything from a few strings of tiny bubbles to a mound of them. Bubble nests aren't anything extordinary, they just mean your betta is mentally and physically healthy enough to breed. While it can mean that, many people take it that there bettas are happy and healthy. However, lack of bubble nests aren't to be taken as bad per say. Some bettas just don't blow bubble nests. Also, sometimes bubble nests are destroyed in tanks if the filter is too strong, or the air is too dry.