I got a V-tail betta. He usually swims in my 30 gallon tanks with 3 mickey mouse fish, a few dano, a moontail betta and a few tetra that look like ghosts. They usually are fine with plain tap water, but recently the tap water was pure white so I added some Fresh Start. They started acting weird like they are trying to get air so I move them to my 20 gallon tank that has 5 tiger barbs in it. The other fish returned to normal, but my V-tail betta went into hiding under my filter. Just to be clear I know the 20 gallon is overloaded I'm just waiting for my water to return to normal, so I can place my fish back in the 30 gallon. My V-tail betta usually swims around not caring about anyone in the tank.