He is in a 15gYou mean like an air stone? Pro would be more surface agitation and bubbles, yay for bubbles. Con would be bubbles, lol some bettas hate movement. How big is your tank? If big enough it should be ok as long as there’s an area without much movement. Other bettas love swimming in bubbles.
They do I have my output nozzles both covered with round media sponges that is why I was thinking I might need a bubbler but if not even better just more noise lolIn my believe a betta is one of the species that can live in water that's pretty low on oxygen (aisn't that why they got the second breathingsystem) From that point of view I'd say it isn't needed (even in smaller tanks). Don't they hate too much sutfaceagitation?